Phelps (elbow) will throw a bullpen session at Tropicana Field on Friday and will follow up with a simulated game if all goes well, Greg Johns of MLB.com reports.

EDGE Analysis

The hard-throwing right-hander appears poised to make significant progress towards a return with the activity planned for him over the next few days. If Phelps progresses through both the bullpen and simulated game setback-free, he's expected to be activated approximately halfway through the Mariners' 12-game road trip that begins Friday.