Castro getting MRI on hamstring, Harris to be examined soon

Though the Nationals do not believe Starlin Castro's hamstring cramp is serious, they will have the veteran infielder undergo a precautionary MRI to check for anything that could sideline him longer than another day or two.

Castro pulled up a bit while running from first to third base during the seventh inning Tuesday in Jupiter, Fla., and was removed from the game. Afterward, he described it as a "cramp" and said it didn't compare at all to previous, more severe hamstring injuries he has suffered during his career.

Davey Martinez originally planned to play Castro tonight against the Astros, his second straight start at third base, but the manager decided not to take a chance until MRI results are known.

"He says he feels fine, but we're still in spring training," Martinez said during his pregame Zoom session with reporters. "I want to make sure. He's done well and he feels good. At this point, I just want to make sure when he goes back out there he's 100 perfect."

Martinez described Castro's status as "day-to-day." The injury comes at a particularly disadvantageous time, just as the Nationals were starting to give the veteran middle infielder a late-spring look at third base in case they decide to start him there over the struggling Carter Kieboom.

Castro, who turned 31 today, has only 45 games of big league experience at third base but spent considerable time the last two winters working at the position and insists he's prepared to play it if needed.

"That's something that doesn't take me for surprise," he said Tuesday. "I'm ready for it."

Castro expressed the same sentiments to his manager, who originally was hoping to get a more extended look at him at the hot corner before the injury occurred.

"I wanted to get him back-to-back days over at third base," Martinez said. "But I talked to him today about playing third base, and he reiterated that he feels comfortable over there. He's fine going over there. It's no big deal. But still I want to see him play over there."

Kieboom will start at third base tonight, hoping to pick up where he left off over the weekend, when he doubled in back-to-back games. The 23-year-old is batting a mere .167/.211/.278 in 15 games this spring.

Josh Harrison, meanwhile, is starting at second base tonight. If Castro does end up as the opening night third baseman, the Nationals would need to select a new second baseman, with veteran utilityman Harrison and 20-year-old prospect Luis García the most likely options.

* Will Harris is scheduled to fly to St. Louis in the next day or two and be examined over the weekend by a specialist who will determine what, if any, treatment is necessary after a blood clot was discovered in the reliever's right arm.

Dr. Robert Thompson is a well-known vascular surgeon who has treated many professional athletes dealing with these kinds of issues, including those diagnosed with the more serious thoracic outlet syndrome.

The Nationals won't know Harris' prognosis for recovery until he is examined by Thompson, but it's all but certain he won't be on the opening night roster.

* Prior to tonight's game, the Nats optioned right-handers Ryne Harper and Dakota Bacus to Triple-A Rochester, reducing the number of remaining candidates for the final couple of spots in their opening night bullpen.