WEST PALM BEACH, Fla. -- Right-handed reliever Will Harris was diagnosed with a blood clot in his right arm, and he will seek further medical attention, the Nationals announced on Friday.

Harris pitched one frame in a “B” game last Saturday to work on his curveball. It was then that something didn’t seem right to the nine-year veteran.

“He felt weird his last outing,” manager Dave Martinez said on Friday. “So, we kind of backed off a little bit, got an MRI and in the arm [there] was a little small blood clot.”

The plan is for Harris, 36, to travel to St. Louis to meet with specialist Dr. Robert Thompson. A date for the appointment has not yet been set.

“For me, it's hard, because medically I don't know the extent of what that is,” Martinez said. “But I know it's something that is serious. We need to take care of it -- take care of it as soon as possible.”

Harris has been preparing for his second season with the Nationals. He has appeared in two Spring Training games, and he allowed one hit and struck out one batter over two scoreless innings. He has held opponents to a .143 batting average.

“I feel for Will, because I know he was just working his tail off to help us this year,” Martinez said. “Here's another guy that, man, he's a workhorse, a guy that throws 70-plus innings in a full season every year. I just hope that when the doctor does see him, we can take care of it and get him back as soon as we possibly can.”

The Nationals constructed their bullpen this offseason to have depth among their relievers. They signed lefty Brad Hand to close games, and Harris, Daniel Hudson and Tanner Rainey are all in the mix for late innings and games in which Hand is not available to close.

It’s too soon for the Nats to make a decision on who would step into Harris’ position -- if need be -- but they have options, including Kyle Finnegan and Wander Suero.

“I don't know much about what's going to happen here,” Martinez said. “But for me, when somebody mentions something like that, it's kind of a scary deal. Until we know more about it, then I’ve got to assume that he's going to not start with us this season, and plus he missed some time. But until we get a clear understanding of what exactly is going to happen, I can't comment on it as much as what I know now."

Harris signed a three-year deal with the Nationals in January 2020. Last season, he battled injuries and pitched 17 2/3 innings with a 3.06 ERA. In ‘19, he led American League relievers with a 1.50 ERA as a member of the Astros.

"He's pretty upbeat considering what's going on,” Martinez said. “Hopefully we'll know more sooner than later, and then we can determine what's going to happen."