Can the Raptors afford to keep Biyombo beyond this season?

There are few names that appear with a certain degree of consistency among the Toronto Raptors‘ most effective lineups.

Two of them are pending free agents. Will both be back?

One is a name most would expect. DeMar DeRozan is having the best season of his career. This summer he’s expected to opt out of his contract and all indications are that, as a two-time all-star, one of the NBA’s leading scorers and just 26 years old, he’ll be swamped with offers the maximum teams can pay him.

The incumbent Raptors will be able to offer him a five-year contract starting at approximately $25.3 million (based on a projected $90-million salary cap), with raises of 7.5 per season. New teams will only be able to offer him four years starting at the same amount, but with raises capped at 4.5 per cent.

Either way, DeRozan will be rich. With the Raptors being able to offer him $145 million over five years and other teams limited to $107 million over four, you would have to think they have the inside track.

The other pending free agent anchoring many of the Raptors' best lineups?

Bismack Biyombo, the Congolese centre the Raptors were able to sign for two years and $6 million (the second year of the deal is a player option) after the Charlotte Hornets decided the former No. 7 pick in the 2011 draft wasn’t worthy of qualifying offer.

Biyombo has been at the forefront of the Raptors' transformation into at least a respectable defensive team this season. His no-holds-barred energy off the bench and capable moments as a starter has been a big part of Toronto's franchise-best regular season.

Raptors head coach Dwane Casey is unreserved in his praise for Biyombo, calling him an "elite defender." Offensively he struggles, but there are signs of growth. His free-throw shooting is a career-best 64.5 per cent, compared with 46.4 per cent as a rookie.

He was essential in the Raptors' surprising win over the Milwaukee Bucks on Tuesday night. While he had several of his signature blocked shots at the rim, he also stepped out to 12 feet to fluidly can a jumper in the first half and made a gorgeous spin move through the lane for a dunk in the second half. He is determined to grow his game, but understands it’s his defence that earns him his floor time.

“If there is an opportunity to score, I’m going to score,” Biyombo said in a recent interview. “My percentages have gotten better and better and better. My free throw shooting has gotten better and better. So it’s exciting for me. But I don’t want to forget what the team needs because that’s what’s going to help the team.”

Biyombo came to Toronto in part because of his close relationship with Raptors general manager Masai Ujiri, who he got to know through the NBA’s Basketball Without Borders program. It’s proven good marriage, so good that Biyombo sounds pretty open about staying long term.

“I love the city. I love the organization. I love my teammates,” he says. “So I have no doubt [free agency] will be handled pretty well once the summer comes. For now my focus is helping this team get to that level the city is excited about, not just being in the playoffs but going far, making history. I want to be part of the history. At the end of the day the rest will be taken care of.”

The challenge for the Raptors is unlike with DeRozan, in Biyombo’s case they have no particular advantage over the rest of the league because they don’t have his “Bird rights” -- the ability to sign him to a longer or more lucrative deal -- and perhaps more crucially, the ability to sign Biyombo to a deal even if the contract amount put the Raptors over the salary cap.

This is a problem, because Biyombo has proven to be a valuable piece for the Raptors and a player who, having just turned 23, still has considerable upside.

In a season in which Jonas Valancuinas has already missed 18 games with injuries -- and it could be 19 if his bruised hand causes him to sit out again Thursday night against the Indiana Pacers -- the Raptors are 12-7 with Biyombo as a starter.

Between his intelligence anchoring the back line of the Raptors defence, his second-to-none work ethic and his condor-like reach, Biyombo has proven himself as one of the NBA’s best shot blockers, most active rebounders and all-around best defenders, one of the few at his position who can put some pressure on the ball-handler in pick-and-roll situations and still scramble back to the paint to protect the rim.

According to Basketball-Reference.com, Biyombo ranks second in the NBA in block percentage, fourth in rebounding percentage and 18th in defensive rating. And it’s not a contract year thing.

Since 2013-14, Biyombo has (on a per-36 minute basis) averaged 12.4 rebounds and 2.8 blocks per game.

How much is that kind of production worth? It’s hard to project.

The only big men age 25 or younger who approach those statistical thresholds are Rudy Gobert of the Utah Jazz and Andre Drummond of the Detroit Pistons. Gobert is two years from free agency, but Drummond -- a restricted free agent this summer -- has already been called a ‘max player’ by Pistons owner Tom Gores. It’s expected he’ll sign a five-year deal this summer that will likely be worth $120 million.

Cleveland's Tristan Thompson, who plays a similar role for the Cavaliers as Biyombo does for Toronto though with more varied defensive responsibilities, signed a five-year, $82 million contract last summer.

Closer to home, Raptors teammate Jonas Valanciunas, a more polished scorer than Biyombo but not his equal defensively, signed a four-year, $64 million extension that will kick in next summer.

Can the Raptors keep Biyombo? It will likely require some significant salary cap magic and perhaps some sacrifice on the part of the likes of DeRozan, who could open up additional room by taking a contract that’s a little less than the maximum but still more than any other team can offer. But as it stands now the Raptors have about $89 million in salaries and cap holds on the books for next summer. Finding a way to fit another $10 million -- and that is likely being conservative -- for Biyombo won’t be simple.

And unlike a year ago, there won’t be a shortage of suitors.

“I expect it to busy,” says Biyombo. “I know there are going to be things to handle, but for me if I focus on my free agency it will be a distraction … once the season is finished and we’ve accomplished our goals and we feel good about ourselves, then we can think about that. But that’s the last thing I’m thinking about.”

For the Raptors it’s a subject that will very much need to be top of mind.