With Kyrie Irving on the trade block, the Eastern Conference champion Cleveland Cavaliers' look may be fragile. This summer has been a mess, no one knows what they'll look like next season and LeBron James could be elsewhere a year from now.

For the Toronto Raptors, a team that has been trying -- and failing -- to end LeBron's reign in the East, this is an opportunity. Having re-signed Kyle Lowry and Serge Ibaka to three-year deals, they have a clear opportunity to take the next step. But an essential question remains unanswered, and it involves the other 2011 top-five pick who has been the subject of trade rumors. What will they do with Jonas Valanciunas?

Valanciunas, 25, was seen as the future of the franchise in 2013, when Toronto reportedly rebuffed the Oklahoma City Thunder's  request to include him in a trade for James Harden. The 7-foot, 255-pound center had the potential to be dominant at both ends. He's big enough to protect the rim, mobile enough to defend pick and rolls and skilled enough to demand double teams in the post. 

Now, five years into his career and the second season of a four-year, $64 million deal, he is often described as something of a relic. The Sporting News' Sean Deveney reported that the Raptors tried to move Valanciunas at February's trade deadline, around the draft in June and since, but have been unable to find a suitable deal. Toronto president Masai Ujiri insisted he is "not trying to give him away," but did not deny that potential trades were discussed. 

Part of the Valanciunas conundrum is that -- were he a bit better in a few areas -- he could be a star. The Raptors have been waiting for those improvements and may be tired of it. He is neither a clever nor frequent passer, his moves in the post are too deliberate and he struggles at times to hold his position on the block. Most important, he has not become the defensive force they desired. Given that Ibaka is a better center than power forward, sending the large Lithuanian away would be understandable. It also would be a bit of a bummer, as a fully realized version of Valanciunas remains a scary thought. 

We can quibble about Valanciunas' place in the modern game, but these issues go beyond his inability to space the floor to the 3-point line or guard multiple positions. Greg Monroe was one of the best sixth men in the league last season. David Lee was an extremely effective reserve on a Spurs team that won 61 games. Valanciunas' $15.5 million salary next season isn't insane, and Toronto should not trade him for nothing. But the league is saturated with centers, and he has yet to display the feel that makes other big men of his ilk stand out. Marc Gasol compensates for his relative lack of athleticism with incredible anticipation and timing. Marcin Gortat averaged 6.2 screen assists per game last season. Robin Lopez does nothing fancy, but almost never does anything wrong. 

Valanciunas' biggest strength, as seen most clearly in the playoffs against the Cavs, is his ability to finish out of the pick-and-roll. He scored 1.3 points per possession as the roll man during the regular season, per Synergy Sports; the only starting-caliber centers better in that category were DeAndre Jordan, Rudy Gobert and Tyson Chandler. He has pretty good touch in the post, too, and those post-up possessions diversify Toronto's otherwise predictable attack. For years, there have been calls for the Raptors to give him the ball more, most recently by Hall of Famer Sarunas Marciulionis, who claimed that Lowry probably couldn't spell "pass." 

That line of thinking, though, doesn't hold up to scrutiny. Raptors coach Dwane Casey told ESPN's Zach Lowe that he tells Valanciunas he has to dominate at the rim and "get every offensive rebound" to earn minutes -- but there's little evidence that force-feeding him is the answer. Valanciunas scored 0.9 points per possession in the post last season, per Synergy Sports, and when he's down there, he cramps spacing, especially when DeMar DeRozan -- the king of the mid-range -- is on the court. Every now and then Casey will mention he thinks Valanciunas will eventually shoot 3s, and he actually made one in the final game of the regular season, but it would be stunning if this were a consistent thing anytime soon. Regardless, the bigger problem is at the other end of the court -- he's not as quick as he was when he was a skinny rookie, and his shortcomings defending pick-and-rolls have led to him being benched in key situations.

Valanciunas' minutes have slightly decreased for three straight seasons. In this past season's playoffs, he started only six of 10 games, perhaps providing a glimpse of a future where Ibaka starts at center and the team can spread the floor, move the ball and switch just about everything on defense. Broadly, the Raptors need to change their identity, a point Ujiri made as directly as possible after Cleveland embarrassed them. Lowry, DeRozan and Ibaka are not going anywhere, so a Valanciunas trade is the only logical way to get more dynamic and versatile in the short term. 

A trade before training camp is possible, but as things stand, Valanciunas figures to remain the starting center. This would mean that Ujiri's "culture reset" would have to wait. His best strategy might be standing pat and hoping that, having heard all the criticism and speculation, Valanciunas comes back motivated to prove he can reach another level. If he starts the season strong and the Raptors are winning, he would have more value in trade -- whether teams see him as they have or in a Monroe-like reserve role. 

Of course, if Toronto goes this route, that comes with risk, having already lost two of their best defenders, Patrick Patterson and P.J. Tucker, in free agency. If Valanciunas is the same guy or regresses, then they may not even be the same old Raptors, unable to hang with the league's true contenders. They could find themselves taking a step back at the same time as the Eastern Conference champions.