DETROIT -- After the Mariners' 2-1 loss against the Red Sox on Sunday, right-hander Taijuan Walker did not travel with the team to Detroit, as he returned to Seattle to have an MRI on the foot. Walker has been dealing with the pain over his past two starts.
Walker left Sunday's start after five innings due to lingering tendinitis. The official diagnosis, dating back to his previous start in St. Petersburg, is posterior tibial tendinitis, which is soreness in the tendon that runs alongside the Achilles in the arch of his right foot.
The righty was having a tough time pushing off the mound Sunday, but was able to get through the fifth without allowing a run. Seattle manager Scott Servais said everything seemed OK on Monday, but that he would feel better if Walker had testing done on his foot.

Walker's next start would be Friday when the Mariners return to Seattle to face the Cardinals. Servais said it is up in the air whether Walker will be able to start. It depends on the MRI and how he feels if he is able to throw later this week. Servais said the team could wait on a decision until as late as Thursday.
Walker is the third injured pitcher in Seattle's rotation. Ace righty Felix Hernandez has been on the DL for three weeks with a strained right calf and lefty Wade Miley went on the DL on Friday with a sore throwing shoulder.
"It's tough," Servais said. "We will get Wade back pretty soon, so that helps. Felix is feeling better. He had a good report today, so he's moving in the right direction. It's just disappointing and disheartening, especially if Taijuan is going to be down for any amount of time."
Miley threw lightly Sunday and Monday, and is expected to rejoin the rotation when he comes off the DL.
The Mariners are wrapping up a three-city, 10-game road trip with a four-game set in Detroit. They are 21-15 on the road, despite a 3-8 mark in their past 11 away from Safeco Field, including a 2-4 start to the trip.