BALTIMORE -- Yankees All-Star infielder Gleyber Torres was in New York's lineup against Baltimore on Monday, batting fourth as the Yankees' designated hitter, a day after he was removed from Sunday's 7-4 victory over Boston with what manager Aaron Boone described as "a core issue."

Torres was sent to New York-Presbyterian Hospital for tests after feeling rib soreness on Sunday night, but he had an ultrasound and took some medicine and reported to Camden Yards feeling much better, he said before Monday's game, adding that he felt good enough to play the field.

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“First of all, I feel good,” Torres said at his locker on Monday. “Last night I felt something different in my body. In that moment I didn’t know what it was exactly, I was just trying to tell the trainer. After that moment I went to the hospital. I got a lot of tests if I had a hernia or something like that, but all good. I took a pill last night and right in the morning today, and I feel so [much] better right now.”

Torres said he underwent a number of tests on Sunday -- including an ultrasound but not an MRI -- and there was no proof of a hernia or of serious damage. He and Boone are not sure what might have caused the ailment, but Torres theorized that it could have been due to “too many hard swings.”

“Not groin, no hamstrings, no hips -- nothing like that,” he added, pointing to a spot just below his right abdominal area. “I feel good. Just like I said, I just felt a little bit sore last night. For sure, I just want to play -- 100 percent. … I’m surprised a little bit I am DH, but like I said, I’m ready to play and be ready.”

“It’s been a crazy year in that way, with the amount of things that have happened to guys physically," Boone said on Sunday. "But it’s also been something that has been a real rallying cry for us. I think it has not just brought a level of physical toughness to the room, but it has forced guys to be mentally tough as well."

Boone said that he did not know when Torres sustained the injury, though television replays captured Torres wincing as he ran to first base on a fifth-inning groundout. Torres remained in the game until the eighth inning, when DJ LeMahieu replaced him at second base.

“No, they ran a number of tests on him and tried to rule out everything,” Boone said Monday when asked if there was any reason Torres did not receive an MRI. “Just the improvement that he started to feel even overnight was encouraging.”

The core injury is the second of the week for the Yankees, as Luke Voit is facing potential surgery for a sports hernia that was initially diagnosed as a lower abdominal strain during the London Series. Boone said that he would not necessarily draw a line between the Torres and Voit injuries.

“I would say we’re always looking at things we’re doing," Boone said. "Maybe even more so this year, just because we’ve had so many things come up. … But the core stuff, every case is a little bit different, so I wouldn’t read too much into it."

Sunday's game also featured a sequence in which Gio Urshela fouled balls off of both legs during a sixth-inning at-bat against Ryan Weber. Urshela was not in Monday's lineup, though he said he would still hit the weight room and batting cages as he spoke to reporters with a wrap on his right leg and bandage on his left shin.

Urshela, for his part, said he could have played if needed Monday and that it’s his right knee that is bothering him more than his left shin. Boone didn’t rule out using him later in the game.

“It’s not as [bad] as it looks. It feels like if they need me, I could play today,” Urshela said. “It’s better than last night. I woke up this morning and started walking like better. Just a little sore.”

Boone did say that even with the injuries to Torres and Urshela, his plan all along was to DH noted Orioles tormentor Torres Monday and sit Urshela as well.

“I kind of had it in mind actually for a couple days,” he said. “Even with Gio, I was planning on this first day probably having Gio down, and it just so happened with the foul balls and everything last night it kind of worked out that way.”