In 2009, the Raptors drafted DeMar DeRozan with the intent of watching him eventually solidify a role as the team's primary wing scorer, an above average option in the backcourt who by the time his second contract came around could possibly surpass the team's former number one overall pick, Andrea Bargnani in terms of overall offensive responsibility. Unfortunately, things haven't quite worked out that way.
After showing very little to zero development from his second to third season, the Raptors have appeared to go in another direction, selecting Terrence Ross, a player who's skill set rivals Derozan's, with the eighth overall pick in the 2012 NBA draft. DeRozan's field goal percentage dropped four points from 2010/11 to 2011/12, and his per game scoring went from 17.2 PPG to 16.7 PPG.
As SI.com's Zach Lowe points out, the Raptors will likely play a "wait and see" game with Ross before deciding what they want to do with DeRozan:
"… The Raptors’ drafting of Ross was a clear signal that the organization is ready to move on from DeRozan next summer if he doesn’t develop, or if his price in restricted free agency climbs too high. The Raptors are on pace to have a decent chunk of cap room — something like $10 million — even after overpaying for Landry Fields.
But they could have max-level room without DeRozan’s cap hold, and given that DeRozan is still just 22 with room to grow, he may be in line for one of those four-year, $28 million deals that can hamper a team’s flexibility. Smart organizations understand the value of replacing so-so veterans with nearly equivalent players on rookie deals."
As Lowe correctly points out, the chances of Toronto extending DeRozan before he hits restricted free agency are extremely small and highly unlikely. If he isn't willing to take a hometown discount, and doesn't show significant improvement this year, there's very little chance DeRozan signs his second contract with Toronto.