The NBA trade deadline is approaching quickly, and the Celtics have limited tools at their disposal to make improvements to the roster.

After the deadline, though, Brad Stevens will have plenty of opportunities to make upgrades via mid-season free agency.

That’s right, folks: It’s almost buyout season.

Now, don’t get your hopes up. No one Boston signs after a buyout is going to knock your socks off. But all the Celtics need is a solid veteran who can step into a bench role every now and then. That’s possible to find, even with some new restrictions on buyout candidates.

There are two ways to approach looking for buyout candidates in the NBA, and they’re pretty similar. You can either scan the rosters of underperforming teams for older players who don’t play much, or look for players on contracts that could become trade fodder in a larger deal. If those players get traded to a team that isn’t a career fit, they might get bought out. The guys on the bad teams have good chances of getting bought out, but those on good teams might require trades, so I’ve engaged in some considerable speculation.

Either way, the player should be in the later stage of his career and on a team with different goals. They’ll receive their salary (or a portion, at least) up front and sign a deal with a team that is in greater need of their services.

For example, some of the biggest buyouts last year were Kevin Love (who went from the Cleveland Cavaliers to the Miami Heat) and Reggie Jackson (traded to the Charlotte Hornets by the Los Angeles Clippers, later signed by the Denver Nuggets).

Like I said: Not gonna knock your socks off – but both of those teams made the Finals, and Love started most of the Heat’s playoff games.

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However, there’s a new wrinkle this year courtesy of the new collective bargaining agreement. Teams over the tax apron can’t sign players who were making more than the full mid-level exception before being bought out. Translation: If Gordon Hayward gets bought out, the Celtics can’t sign him because he makes more than $12.4 million this year. Sorry, folks.

While we’re at it, Kelly Olynyk won’t be in Boston either. He makes less than the MLE, but he won’t get bought out, in all likelihood. He’s too good, and will be traded if the Jazz don’t see him as a part of their future.

But there are some potential buyout candidates Boston could have interest in. I’m going to start with some more speculative and hopeful possibilities, and we’ll get more realistic as we go.

Taurean Prince, Los Angeles Lakers

This is speculative, as Prince is a meaningful contributor on a Lakers team that really relies on 3-and-D guys. Prince came to the Lakers after the Minnesota Timberwolves waived him last summer, and he’s played his role well for Los Angeles.

The reason why I think a buyout is possible is that the Lakers need to make a sizable move to meet high expectations this year. Almost every reasonable mock trade for Los Angeles that I’ve seen includes Prince. Could LA go get Zach LaVine from the Chicago Bulls? Dejounte Murray from the Atlanta Hawks? Prince’s $4.5 million deal would be helpful in facilitating either deal.

The Lakers seem to like Prince – who is averaging 10 points, 3 rebounds, and 2 assists in 30 minutes for LA – but they have other options at the wing, like Jarred Vanderbilt and Rui Hachimura. That means Prince might be on the wrong end of a much-needed Lakers trade. Boston could ease his pain, and he could provide shooting and wing defense out of the gate – in a limited role.

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Delon Wright, Washington Wizards

This one probably isn’t going to happen. Many teams will target Wright via trade, as his defensive prowess as a guard is hard to come by in the league. Plus, he’s on a very reasonable – and expiring – $8 million contract. If Washington can’t find a trade partner, though, and doesn’t want to re-sign him, will they buy him out? They have plenty of guards – and who needs to win games anyway when there’s draft capital to be optimized?

Wright isn’t the kind of player Brad Stevens has indicated he would want from a late-season addition – a big wing. He is, however, a 6’5” guard who can guard bigger guys and bring some bonus ball-movement. Plus, Stevens could get a big wing in a different way. If the Celtics can get the 31-year-old Wright on the cheap after a buyout, that would be a home-run signing.

I’ll try to stay away from other potential buyout point guards, because I’d be surprised if Stevens went out and got someone who would take minutes from Payton Pritchard. The reason I went with Wright is that his skillset is so distinct from Pritchard’s that it might be nice to be able to pick between them off the bench based on matchups in the postseason.

Keep your eye out on Wright’s trade market – if he’s still a Wizard by the deadline, he could make it to Boston.

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Robert Covington, Philadelphia 76ers

Signing Covington, like signing Prince, would require a trade. The Sixers are pretty likely to make one, though. Even if it’s not earth-shattering, they have picks to move and plenty of salary-matching fuel. Covington’s contract is a big piece of a potential package for an upgrade on the wing. If he goes to a team via trade that isn’t contending, they won’t have much of a use for him. At $11.6 million, Covington makes a little less than the maximum possible salary for a Celtics’ buyout addition.

Covington is not the player he was a few years ago, when he averaged 13 points and almost 2 steals and made an All-Defense team. But he’s really large, shoots the ball well, and can fill in at either forward position. He’s also played the five in the last few years, so maybe he could do that for Boston, too.

Covington is in his 11th year as a pro, and is known as a really good guy league-wide. Culturally, he’d be a great addition to the locker room.

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Danny Green

We don’t need to speculate if Green is a potential buyout guy, because he’s already been cut by the 76ers to make room for incoming players in the James Harden trade. (His deal wasn’t guaranteed anyway, so it wasn’t really a buyout). The 36-year-old has only played 13 games this season and last combined, but before that he played more than 60 for the Sixers, averaging six points and a steal in 22 minutes per game.

Green’s a proven shooter and a good wing defender. At 6’6”, he’s not huge. But he’s a wing who wouldn’t have to do much in limited minutes in Boston. After being bought out last year by the Grizzlies, he was in talks to come to the Celtics, but they never reached a deal, according to Bobby Manning of CelticsBlog and CLNS.

Green has mentioned recently that he hasn’t ruled out a return to the Sixers, so maybe he does that. If not, he could be a good presence off the bench for Boston.

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Bismack Biyombo

Even if Biyombo is far from a complete NBA player, he is an established rim deterrent and could be helpful if the Celtics lose a big or two to injury. He started 27 games earlier this season for the Memphis Grizzlies, who are without Steven Adams for the remainder of the season. He’s averaged 5 points, 6 rebounds, and a block in 23 minutes.

Biyombo is also not on a team right now, as he was waived by the Grizzlies earlier this month. If he was to sign with Boston, I wouldn’t bet that he plays over Luke Kornet regularly. But if Boston really needed to scare off points in the paint for stretches, Biyombo could do that.

Danilo Gallinari, Detroit Pistons

We know the Celtics like Gallinari, as Stevens signed him before last season. But after being traded before ever suiting up for a game in green, does Gallinari still like the Celtics?

He would be an excellent fit with this roster. He’s almost seven feet tall, shoots the ball well, and can create his own shot every now and then. He is probably a power forward at this point in his career, but it’s possible he could slide up or down depending on the matchup.

The Detroit Pistons could keep him on their roster, but they have little use for the 35-year-old in the long run.

Blake Griffin

Alright, Griffin isn’t a buyout guy: He’s a regular free agent. But he’s similar to other players on this list – a veteran past his prime who could sign for the minimum and help a good team. Also, he pretty nicely fits Stevens’ description of the big wing he wants to round out the rotation. Maybe he’s more of a five now, but he’s a big body who can still do most things on a basketball court in limited minutes.

Plus, it’s clear that everyone still on the Celtics loves Griffin, and some players even mentioned him during media day this year, as if he was still a teammate.

Griffin chose not to sign with Boston this season to be closer to his family. But I can’t help but think that earning a million bucks and a great shot at an NBA title for just a few months’ work is too good of an offer to refuse. We’ll have to wait and see.