ST. PETERSBURG -- Mariners right-hander Taijuan Walker came out of Tuesday's 8-7 loss to the Rays after 3 1/3 innings due to an aggravated tendon in the arch of his right foot, though he walked off under his own power and says he hopes to be OK for his next start Sunday in Boston.
"It's not as bad as I thought it was," Walker said after the game with his foot wrapped in ice. "It's just a little tendinitis. I felt it in the second inning and just couldn't really push off and use my legs. I've felt it before. I felt really good today, and everything was working. But that's something I can't control."
The hard-throwing 23-year-old struck out the first four batters he faced, but he gave up four runs (three earned) on three hits -- two home runs and a triple -- before being replaced by rookie Edwin Diaz.
Walker had a 5-2 lead in the fourth when he gave up a one-out homer to Steve Pearce. After Corey Dickerson followed with a triple off the left-field wall, trainer Rick Griffin, manager Scott Servais and pitching coach Mel Stottlemyre Jr. hustled to the mound, and Walker was taken out after a brief conversation.
Walker said he had some minor issues with the tendon earlier this season, but he worked through them without missing any time. He felt the problem flare up on a pitch in the second inning, then worsen when he jumped to field a comebacker in the third and again when he ran to cover first on a play to the right side.
"He came out and was throwing the ball really good early," Servais said. "But it was pretty obvious after that [comebacker] that he wasn't quite right and was having a hard time driving off his back foot down the hill. He tried to gut it out and stay out there as long as he could, but you could see there was something that wasn't quite right."
Griffin said the Rays' orthopedist checked out the injury during the game and confirmed that it was tendinitis and inflammation in the posterior tibia, which is a tendon that runs alongside the Achilles and helps control the arch.
"Luckily and gratefully it's not his Achilles," Griffin said. "But when it started to bother him, he was using all arm to throw. He wasn't pushing off. You can't have him hurt his arm because he's favoring his leg."
Walker is 3-6 with a 3.69 ERA and had thrown eight scoreless innings with a career-high-tying 11 strikeouts with no walks in his previous outing, a 5-0 victory over the Indians.
The Mariners are already without ace Felix Hernandez, who has been on the 15-day disabled list since May 29 with a strained right calf and isn't expected back until sometime in July.
If Walker can't pitch in Boston, the Mariners will need to bring in reinforcements, but that wasn't a topic of discussion quite yet.
"Right now, we are hopeful he's going to make his next start, but we'll see how he is over the next couple of days," Servais said.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.