Thompson lands on IL with left knee contusion

CINCINNATI – The Nationals added another reliever to the injured list today, placing Mason Thompson on the 15-day IL with a left knee contusion that appears to have prevented the right-hander from pitching most of the week.

Thompson hadn’t appeared in a game since Monday, when he tossed a scoreless eighth on all of five pitches, helping lead the Nats to a 5-3 win over the Brewers. Despite the team being in several close games since then, manager Davey Martinez did not call upon his top setup man.

Martinez revealed Thompson recently hurt himself after falling, though he did not offer any more specifics than that.

“I don’t know how he fell, but he said he fell and he’s been dealing with it for a few days,” Martinez told reporters before today's game against the Reds. “Hopefully it will go away. He had an MRI that showed he had a contusion. So we’re going to make sure we take care of him and get him ready to go again.”

Though it has been five days since Thompson last pitched, IL moves can only be backdated three days. So he officially goes on the IL on Aug. 2 and will eligible to return Aug. 17.

The Nationals needed to clear a spot on their active pitching roster today for Joan Adon to be called up from Triple-A Rochester for a spot start in place of Trevor Williams, who remains on bereavement leave.

“We had to make a move today, so we decided just to put him on the IL, get him better,” Martinez said.

This is Thompson’s first trip to the IL this season, but the Nats might be able to use it to their advantage and help the reliever overcome some recent mechanical issues.

Thompson has experienced a roller coaster of a season, with monthly ERAs at the two extremes: 1.89 in April, 10.61 in May, 0.82 in June, 9.00 in July. His struggles usually have coincided with an unwanted change to his mechanics, in which he starts short-arming pitches instead of reaching all the way back before delivering.

Even as he struggled, Martinez usually felt compelled to use Thompson in high-leverage spots, especially with Hunter Harvey and Carl Edwards Jr. already on the IL. But in recent days, the manager has instead turned to right-handers Jordan Weems and Andrés Machado and left-hander Jose A. Ferrer for some big outs late in games, leaving Thompson in the bullpen.

Those pitchers will probably continue to be called upon to set up closer Kyle Finnegan while Thompson is out.