Phillies' Giles left game Tuesday with back tightness

Philadelphia Phillies closer-in-waiting Ken Giles had his Tuesday outing cut short after departing with tightness in his lower back. 

Giles said following the game that he isn't worried about missing Opening Day. 

"It's just stiff," Giles told Todd Zolecki of MLB.com. "It doesn't hurt. I'm able to move around and stuff."

However, his manager Ryne Sandberg sounded less optimistic. 

"I'm a little concerned with that, a little concerned with that," Sandberg said.

The right-hander was exceptional through 44 appearances last season, posting a 1.18 ERA and 64 strikeouts in 45 2/3 innings. 

Philadelphia has dealt with their fair share of injuries early on as Chad Billingsley, Cliff Lee and Mario Hollands are all expected to begin the year on the disabled list.