Phillies' Bryce Harper: Working on modified slides

Harper (elbow) took grounders and performed modified sliding drills Tuesday, Corey Seidman of NBC Sports Philadelphia reports.

Harper also continues to move through a hitting progression that now includes high-velocity batting cage work. The biggest concern right now for the Phillies is that Harper might rupture his surgically repaired UCL on a slide, and so they're drawing up ways to prevent that. The superstar slugger has a follow-up appointment later this month with Dr. Neal ElAttrache, who performed his Tommy John surgery last November. The current belief is that he might be able to return to MLB competition sometime in late May.