Zych (biceps) will throw another live batting practice session Sunday, Shannon Drayer of MyNorthwest.com reports.
Zych continues to steadily progress from offseason biceps surgery, though he's still unlikely to be ready for Opening Day as the team eases him back into regular pitching activities. The right-hander is expected to serve an important role in the Mariners' bullpen upon his return, so look for him to return to game action soon if all goes well.