Omar Vizquel felt Victor Martinez’s heart beating.

And it was beating fast.

“Too fast for his speed,” Vizquel said.

They stood at first base in the bottom of the seventh inning of Thursday night’s game against the Rays, right after Martinez’s groundball went under the glove of shortstop Shane Robinson to give the Detroit Tigers a late lead.

Martinez was sweating a lot, felt warm, and mentioned to Vizquel his heart was beating fast. So Vizquel, the Tigers’ first base coach, put his hand on his heart.

“I asked him if he could run and he said ‘No, no, I want to get out,’ “ Vizquel said.

And so Martinez slowly made his way back to the Tigers dugout. At the time, it was thought his knee could be bothering him, or his back.

But Martinez spent Thursday night at a local hospital and was diagnosed with an irregular heartbeat, manager Brad Ausmus said Friday afternoon. He will be placed on the 10-day disabled list.

“It’s a little bit scary,” Ausmus said Friday. “It’s not something at his age that you generally consider an issue or worry about. That being said, I guess making it through is a little bit of an unknown factor, which is probably causing more anxiety than anything else.”

The Tigers called up first baseman/catcher John Hicks from Triple-A Toledo to take Martinez’s place on the 25-man roster.

Vizquel, too, talked to Martinez Friday and said the designated hitter was “feeling good” and is expected to undergo further testing. There is a possibility he could be held at the hospital overnight for monitoring, Ausmus said.

“I didn’t find out about it until really, when he came out of the game because he was playing through it,” he said. “My first thought was maybe dehydration. I’m not sure the doctors even know what caused it or what has caused it. Often times, the body corrects itself on its own. Sometimes it doesn’t, but we should know more tomorrow.”

Martinez, 38, is hitting .261 with five home runs and 29 RBIs this season. He is in the third year of a four-year, $68 million deal signed prior to the 2014 season.