Jonas Valanciunas' development will make or break the Raptors' season

The Raptors had a very busy offseason. After their devastating first-round loss against the Wizards, three of their top-10 minute players are gone, including two of the team's most-used big men. DeMarre Carroll arrived from Atlanta on a big contract, and the expectation is that he'll log several minutes at power forward. Toronto's identity is therefore shifting.

The byproduct of that change is that the training wheels are off Jonas Valanciunas. Now that Amir Johnson is not there to serve as a crutch, Valanciunas must prove he can be a dependable scorer and defensive anchor. The Raptors will need him to realize his potential to be one of the East's best teams.

All Valanciunas needs on offense is a bigger role

The 22-year-old center was among the most efficient post players in the league when he got a chance. He scored the most points per possession among all players with at least 300 post up opportunities while having a manageable 10.5 percent turnover rate in those situations. He was also a very good pick and roll dive man on limited possessions and has the touch to finish around the rim if he's properly fed. Valanciunas can score around the basket and do it efficiently.

But despite those solid numbers, the Raptors didn't trust Valanciunas to carry a large offensive role. The Raptors' backcourt of Kyle Lowry and DeMar DeRozan dominated the ball, and coach Dwane Casey would often sit Valanciunas late in favor of Johnson, Patrick Patterson or even Tyler Hansbrough. As a result, Valanciunas' playing time and scoring dipped significantly in the second and fourth quarters. Toronto made a token effort to get him going early, then ignored him the rest of the game.

Valanciunas is not without blame for his small role. His decision-making is more suspect than his turnover numbers suggest. At times, he's too passive. Instead of trying to make things happen, he disappears for long stretches.

Yet the 12 points he scored per game last season are more reflective of a small role than a lack of skills. Now that high-usage guards Lou Williams and Greivis Vasquez and the team's two preferred pick and roll targets from last season -- Johnson and Hansbrough -- are gone, Valanciunas will be featured offensively. If the past is any indication, he should thrive.

JV is a work in progress on defense and the boards

Valanciunas had one of the league's highest individual rebound percentages, yet his team remains average on the defensive boards with him on the court. The addition of a very good defensive rebounder in Luis Scola should help, but JV will need to be more assertive chasing rebounds outside of his area when he shares the floor with Patterson or Carroll as a power forward.

Defensively is where Valanciunas must make the biggest improvement. The Raptors were very bad on that end in general last season, but actually performed worse with him on the court. Alternative options to Valanciunas are more limited this year. Patterson and Scola are too slow, Carroll is not used to playing inside and rim-protecting big man Bismack Biyombo is too limited on the other end to share the court with Valanciunas. Valanciunas will have to mature quickly.

Valanciunas is a good rim protector despite not boasting eye-popping block numbers because he uses his length to allow a very low 46.5 percent on opponent shots at the rim. The problem comes when he's matched up against quicker perimeter players. Valanciunas is one of the worst players at defending spot-up opportunities, according to Synergy Sports. He compounds his lack of foot speed by drifting too far off his man.

Valanciunas must also be more diligent getting back on defense. He crashes the offensive glass hard, but he is too often beat by his man down the court when he fails to secure the board, leaving his team in a precarious position. Last season, the Raptors allowed two more fastbreak points per game when Valanciunas was on the court as opposed to on the bench. That doesn't seem like much, but it's the difference between being one of the top five best transition defenses or being in the middle of the pack.

Off-ball and transition defense require focus and effort. If he puts his mind to it, Valanciunas will improve in both and become a net plus on the defensive end.

If JV doesn't break out, the Raptors are doomed

There's no safety net for Casey anymore. If Valanciunas cannot stay on the floor and anchor the team on both ends, the Raptors will take a step back. How Valanciunas handles the situation will define the Raptors' future. It'll also define his own, since he'll be a restricted free agent next summer.

If Valanciunas really has the talent and the disposition to be a star, he needs to show it next season.