Seager fouled a ball off his leg in the seventh inning of Saturday's game at San Diego. He stayed in and finished that game, but wasn't full speed on Sunday.
"That wasn't the best one. That one hurt a little bit," Seager said Monday. "I squared it up pretty good. But it's feeling better today."
The Mariners need Seager's bat in the lineup. Going into Monday night's series opener against Oakland, the 24-year-old from North Carolina was leading Seattle in RBIs (45) and doubles (19) and was second in home runs (10).
Seager hit .320 (8-for-25) with two home runs and six RBIs on the road trip to Arizona and San Diego, including a pinch-hit double in the eighth inning of Sunday's 2-0 loss to the Padres.
He'd gone 0-for-9 the first two games in San Diego before his pinch-hit in the finale but said he felt good at the plate throughout the trip.
"I had some good swings, but just got unfortunate," Seager said. "I hit the ball hard, but just didn't have a lot to show for it. But that's kind of the way baseball goes. Arizona went well and, from an offensive standpoint, San Diego was just one of those series. But I felt fine."
The one thing he'd like back Sunday was getting doubled off second base when Justin Smoak followed with a line drive that was caught by Padres second baseman Alexi Amarista, who had shifted over to shallow right field.
"I knew they were shifting and everything, and when he first hit it I kind of paused because of the shift," Seager said. "But I saw it go over the first baseman's head and I thought it was down. I took a couple steps and then realized he was right there, but I didn't have time to get back.
"The shift throws a little wrinkle into it, but I've got to do a better job of knowing where the defense is. So that was on me."