The Raptors announced Monday that rookie Jonas Valanciunas, drafted in 2011 and who spent an additional year in Lithuania last season, suffered a calf strain recently. From the Raptors: 

Raptors center Jonas Valanciunas sustained a leg calf strain during a voluntary workout Saturday afternoon.

The injury is not thought to be serious and he will be treated as symptoms require.

A timeline for a return to full basketball activity has not been established.

Valanciunas is expected to be a major contributor to the Raptors this season, allowing Andrea Bargnani to move to power forward, a more natural position. The Raptors also are banking on Valanciunas long-term as the defensive presence down low, so no, this is not good. But Dwane Casey's just glad it wasn't worse. From the National Post

“He felt something pop,” head coach Dwane Casey said on Monday at the Air Canada Centre. “Your first thought is it’s an Achilles tendon [tear]. But it wasn’t. It was a strain.”

via Toronto RaptorsJonas Valanciunas suffers left calf strain.

Yikes. Close call. 

A photo surfaced on message boards Sunday showing Valanciunas in a walking boot, and prompted panic in Raptors nation. But we've seen the use of walking boots become widespread in recent years, even being used for simple ankle sprains. 

All in all, things could have been a lot worse, but with training camp just a week away, this is definitely not how the Raptors wanted to get things started.