PORT CHARLOTTE, Fla. -- Brock Holt 's competition for a roster spot doesn't compare to the battle he had with his own head the past couple of years.

A concussion in May 2016 started a downward spiral for an invaluable utility player who was an All-Star in '15. The after-effects of the concussion morphed into vertigo early last season, when Holt felt like he was in a fog for weeks.

Now, he is of clear mind and able to play with abandon. He added two more hits and an RBI in Wednesday's 8-3 win over the Rays and is hitting .345 in Grapefruit League action.

"I feel really good," said Holt. "I feel healthy, that's the main thing. I feel good, I feel better than I've felt in a long, long time so I'm taking that as a positive and trying roll with it. I had a good offseason, came in feeling good, feeling strong and still feeling good a week out [before the season], so it's been good."

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The past two years were not good, as Holt slashed .237/.316/.337. Compare that to 2014-'15, when he had a .280/.340/.380 slash line and was known as Brock Star. He gave the Red Sox a player who could hold his own at seven different positions. Now, he can offer that versatility again, and hopefully the revived offense to go with it.

There were times last year when Holt was just trying to get through the day.

"Just, vision and stuff, it was all messed up," Holt said. "It's one of those things, no one could tell me exactly what I needed to do to get back, so I didn't know how long it was going to take, if it was going to get back to normal, stuff like that."

Everything feels clearer now for Holt, who found a medication late last season that seems to have curbed the problem. He takes it every night.

"Last year, I was swinging through pitches and I'm not really going to strike out a whole lot, and I was literally swinging through fastballs right down the middle, and I was like, 'What the heck is going on?' And I feel like my at-bats this spring have been really good," Holt said. "I just feel like I'm able to lock in, to focus a lot, a lot better than I was last year. Obviously, you've gotta be able to see to hit, so I think that's been the biggest thing. My vision is clearer.

"I'm able to focus better on the ball and I don't have a lot of, you know, lag in my sight. I feel like last year it was kind of, I'd move my head real quick and it'd take awhile for it to settle. Everything is pretty clear. I feel a lot more comfortable in the box, and I feel like it's shown in my at-bats."

That said, the Red Sox have a loaded roster in which the talented Blake Swihart , who is out of Minor League options, is probably a lock for one utility spot. That leaves Holt trying to fend off Deven Marrero for the other one.

Holt has to be considered the favorite, given his track record. But Marrero, a first-round Draft pick in 2012, is out of options. Holt, 29, surprisingly still has a Minor League option left.

"Yeah, I'm not too worried about it. If the Red Sox don't want me on the roster, I'm sure there's 29 other teams that would be happy to have me on the roster," Holt said. "That's one of those things, you don't worry about it. I feel like I'm deserving of a spot on the team and I think if you ask anyone in the clubhouse, they would say the same thing. So I'm not too worried about it. Whatever happens happens, and you go from there."

Red Sox manager Alex Cora, a utility player during his career, understands the situation Holt is in.

"I was part of that my whole career. In L.A., I was a lock. Here with the Red Sox, I was a lock," Cora said. "Then after that, you just play. You really don't think about it. If you're confident enough, you'll be fine. You can't let that control the way you act in the clubhouse or who you are as a player. He's been great. He played good defense. He's putting good at-bats. He's a good baserunner. And the situation they're in, they just have to play. Control what you can control, and we'll see what happens at the end of the week."