TORONTO - Jonas Valanciunas does not play late in close games against smaller, quicker teams and whether or not you agree with the rationale behind it, that's unlikely to change anytime soon.

The Raptors' starting centre and fourth-leading scorer has not logged a single fourth-quarter minute in 15 of the 48 games he's played this season, including Monday night's disappointing 82-75 loss to the Bucks. In the fourth quarters he has appeared in, he's averaging just 5.4 minutes, which ranks 10th on the team.

It should come as little surprise to see Valanciunas on the bench in crucial late-game situations. This is not a new development, Dwane Casey has long been reluctant to trot out the seven-footer with the outcome of a game on the line, especially when the opponent forces their hand.

"Usually if we're scrambling, double-teaming, trying to get back defensively, trying to play fast, in those situations JV is not in the game," Casey said after practice on Tuesday, asked about his preference to sit Valanciunas in crunch time. "Last night we gave up a couple of threes because we were slow from one of our bigs to rotate. And they're playing [Jared] Dudley, who is usually a three-man at the four, in that situation." 

"We needed to get faster in our rotations, and we did that with Tyler [Hansbrough] and [Patrick Patterson]. No disrespect to JV."

On Monday, Valanciunas was the only player that offered Toronto any kind of advantage over the Bucks' stifling defence. The Raptors' centre recorded a double-double of 12 points and 10 rebounds in the first half, hitting six of his nine shots. He played seven minutes in the third quarter without logging a single attempt, getting few touches in the post, before sitting out the fourth.

That decision, as Casey explained, is one that has been made with defensive versatility in mind. While Valanciunas has made significant strides as a defensive rebounder and rim protector in his third NBA season, he still lacks the lateral quickness and knowhow to help on pick and rolls and race out to the three-point line to contest smaller bigs.

These limitations are physical, more than anything else. As a seven-footer, listed at 255 pounds, it's tougher for him to adapt if and when he's the only traditional big man on the floor. It almost has nothing to do with his body of work through three quarters, the final 12 minutes are its own entity. 

"If I had Tyson Chandler, he probably wouldn't be in the game," Casey added. "It's no disrespect. It's just the style of play. If JV is dominating offensively in that situation, we would probably keep him in. Our issues were that we needed energy, we needed speed. We needed something to get us going in our rotations. And that's just not his attributes. It's not one of his assets that he has. It's nothing against him. It could be anybody. I think that's something that's been established. Unfortunately we've been in those situations a lot in the fourth quarter, where we needed some speed or have gone small, and Amir [Johnson] and Pat, and last night it was Tyler that gave us that defensive energy we needed."

For most of last season and the first half of this one, the Raptors have been a better defensive team with Valanciunas on the bench. Valanciunas is one of four Raptors (Landry Fields, Lucas Nogueira and Bruno Caboclo) and the only regular with a negative net rating, meaning the team is allowing more points than they are scoring with him on the floor. When Valanciunas sits, Toronto outscores opponents by 12.0 points per 100 possessions, the highest net rating on the team.

Defensively, they have had far more success when pairing two of the smaller bigs together this season. Hansbrough and Patterson have a net rating of 14.2 in 452 minutes together, while the Johnson and Patterson tandem has bested the opposition by 11.1 points per 100 possessions in 267 minutes together. Valanciunas and Johnson, the team's starting frontcourt and one of their most used pairings, have been outscored by 2.0 points per 100 possessions in 816 minutes. Valanciunas and Patterson are a minus-1.1 in 399 minutes.

Casey and the Raptors' coaching staff have done a good job in managing the 22-year-old's expectations and ensuring that he remains focused on working hard and doing the little things they need him to do on the court. Although it's disappointing to sit on the bench during the game's most critical moments, as it would be for any player, Valanciunas is not hanging his head or questioning the coach's decisions.

"I'm just doing my stuff," Valanciunas said. "I'm not frustrated. Some nights I'm playing four quarters, some nights I don't but it's a different matchup every night."

"A lot of teams go small on us, so coach is probably trying to match their small players," he continued. "When they go small they can shoot so it's hard for me to go out to the three-point line and guard the shooters. So he's just trying to match them, I guess."

Casey has been hesitant to impose the team's size advantage without full confidence that the pros on offence will outweigh the cons defensively. He said he strongly considered subbing Valanciunas in late against the Bucks but the defence of Hansbrough and Patterson had helped them get back in the game, holding Milwaukee to nine points on 24 per cent shooting over the final 12 minutes.

Offensively, his game continues to grow. He's averaging 12.5 points on 56 per cent shooting this season, both career highs. With time, experience and some offseason work, Casey is confident that his defence will catch-up and believes Valanciunas will blossom into a closer.

"His next evolution as a player is to be able to rotate out to the three-point line and do that," the Raptors' head coach said. "That's going to be his next thing: to be able to rotate, move his feet, guard smaller players on the perimeter in our rotation."

"I think he can [play late in games eventually]," he continued. "I think, oh definitely, he can be in the game. Somebody asked if it's something he can develop - he's getting there. He's better this year than he was before in his first couple years in the league, of guarding perimeter guys, staying in front, staying down in the stance. He's getting better." 

"Is he there yet? No. But also there are other areas that other players are not as good at. He's going to get there. We all want him to be that guy today, tomorrow, yesterday. It just doesn't happen in this league. I want him to be that, too. There is no magic wand. The only thing you can do is [let] time [pass]. He's a great kid. He's going to be a great player in this league someday."