He said the arm is sore but didn't rule out playing Friday night against San Francisco.
Rays right-hander Alex Cobb, coming back from Tommy John surgery 13 months ago, will throw 15 fastballs in his first batting practice session Saturday.
Cobb will have three or four BP sessions on a five-day schedule before starting a minor league rehab assignment. He might return in late July or early August.
Tampa Bay placed right fielder Steven Souza Jr. on the 15-day disabled list with a left hip strain. He was hurt diving for a ball Tuesday night. Left-hander Blake Snell, a native of the Seattle area, was recalled from Triple-A Durham to start Thursday's game.
"I'm pretty pumped about it," Snell said, according to The Seattle Times. "I will be pretty jittery facing the Mariners. It's a team I watched my whole life and I always rooted for. It sucks to root against them now, but I'm getting used to it."
The Associated Press contributed to this report.