CINCINNATI -- There was some relief for Reds rookie center fielder Nick Senzel after he learned that the dizziness that forced him out of Wednesday’s game at Milwaukee wasn’t a return of vertigo symptoms.

Apparently, Senzel was having a reaction to allergies.

“I feel a lot better than I did in Milwaukee,” Senzel said on Friday afternoon before the Reds’ 12-2 loss to the Rockies. “They think I grew up with some bad allergies and that in certain places my allergies triggers that [dizziness].”

Senzel, 23, has experienced issues with vertigo twice before -- including a stretch last season where he missed a month for Triple-A Louisville. Vertigo is an inner-ear condition that can cause a loss of balance and dizzy spells.

“Was what happened the other day vertigo? No,” Senzel said. “But I think in the past having it, there’s a big mental hurdle you have to get over. It’s hard to describe. You just don’t feel like yourself. We’ve done every test. I’ve done everything rehab-wise to make sure that’s fine. Now I’ve got some allergy medication and feel a lot better.”

Senzel was also wearing glasses with blue-light lenses but didn’t plan on using them during games.

“I’m just going to start wearing these so my eyes don’t get strained,” Senzel said. “I’m just wearing them, trying them out. Nothing really to look into.”

Senzel has dealt with some nagging injuries this season -- including being hit in the eye by a foul ball off the dirt, spraining his right ankle during a crash into the wall, dealing with a tight hamstring last week and he once left a game with a migraine headache.

Reds manager David Bell felt that Senzel was ready to play but decided to start Jesse Winker in center field.

“It gives us one day to allow him to go out into the heat and move around, just to be sure, so he doesn't have to think about it more than anything,” Bell said.

Following Wednesday, Senzel noticed some backlash on social media that left him stung.

“I don’t think it’s fair to me. I don’t think it’s fair to my teammates. I come out here and play as hard as anyone on the field. I want to win. I never don’t want to play,” Senzel said. “It kind of hurts my feelings a little bit. I want to play every single day here. That’s my job to get ready to go every day. When things like this happen, I don’t think people realize how tough it is. Those people don’t matter. The guys in this clubhouse matter, my family and friends. That’s it.”

Barnhart activated; Graterol to concussion list

With Juan Graterol unable to play because of concussion protocol, and the Reds being left with Ryan Lavarnway as their lone healthy catcher, they activated Tucker Barnhart from the injured list on Friday. Graterol was placed on the seven-day concussion list.

Barnhart, who went on the IL June 28 with a right oblique strain, was supposed to get four rehab assignment games for Louisville. Instead, he got one game and was then put in Cincinnati’s starting lineup vs. the Rockies.

“It's probably not ideal for him to only get one game but from a health standpoint, he's in good shape,” Bell said. “He's completely cleared and healthy and ready to go. We're just in a situation where we need to get him here. We're confident that he'll work his way back into, from a timing standpoint and all that, he has the experience to be able to make this happen. It was just a decision we had to make in our catching. we can't wait to get him back.”

In the third inning vs. the Brewers on Wednesday, Graterol had two foul balls ricochet off his catcher’s mask. The second one, by Lorenzo Cain, knocked the mask off and hit his jaw. He had to leave the game.

Graterol, who previously suffered a concussion in the Minor Leagues, reported feeling better. But because he was taken out of a game, rules for the protocol prevented him from playing Friday until he passed a series of tests.

“He doesn't want to miss any time, but at the same time, it makes me feel a lot better, that's for sure, as opposed to running him back out there, that's for sure,” Bell said. “Anytime you have anything going on up there, I'm good with the extra time.”

The Reds could soon get another catcher back as Kyle Farmer began a rehab assignment at Class A Dayton Thursday and will be at Louisville on Saturday. Farmer, who is on the concussion list as well, says all feels well.