Nationals third baseman Ryan Zimmerman said his surgically repaired right shoulder feels worse than it has in the past, even as he waited Sunday morning for the results of an MRI exam.

(Jonathan Newton/The Washington Post) (Jonathan Newton/The Washington Post)

“Through spring and last year and things like that, it felt good sometimes, it felt bad sometimes,” Zimmerman said. “But it’s never really felt like this, and that’s why I said something.”

After making an errant throw in the fourth inning of Saturday’s 6-2 loss to Atlanta – a miscue that prevented Stephen Strasburg from getting out of the inning and led to two runs, turning the game – Zimmerman went to Manager Matt Williams and said his shoulder would prevent him from playing further.

It was a dramatic step for a player who has been a cornerstone of the franchise, and whose $100 million contract extension begins this season. Zimmerman said no decision has been made on whether he will go on the disabled list; a doctor was headed to Nationals Park to review the MRI on Sunday morning. But he is clearly at another low point with a shoulder that first caused problems in 2012.

“It’s just sore,” Zimmerman said. “It was more sore yesterday than it usually is. The last however many years I’ve played when it felt good, I’ve played when it felt bad, and yesterday it felt worse than normal. I thought it was the right thing to tell Matt and see what we’ve got.”

Zimmerman said that the early spring chill – it was 51 degrees at game time Saturday, when temperatures headed to the low 40s – “doesn’t help, but I’ve played in the cold before, and it hasn’t felt like that.”

In an interview over the winter, though, Zimmerman said that he frequently had to go to extreme measures last season when he played in the early season cold.

“When it was cold out, I would have to go – when I wasn’t up every inning – I’d have to go throw inside, or I’d have a heat pack on it,” Zimmerman said in January. “Because when it was cold, it was really bad. I was doing certain things, and on the road I ran into problems, because they don’t have the facilities that we have at home.

“As the year went on, the last month-and-a-half, I really didn’t have to do any of that anymore. I could actually just relax.”

It’s unclear when Zimmerman will be able to relax about the current situation. He is not in the lineup for Sunday’s series finale against Atlanta, replaced at third by Anthony Rendon, while Danny Espinosa takes over for Rendon at second.

Zimmerman said he hasn’t really allowed his mind to think about a potentially permanent switch to first base, where he has never appeared in a regular season game. The problem, he said, doesn’t affect him when he swings. But now a year-and-a-half after surgery, he is frustrated.

“It’s been a tough two-and-a-half years, or however long it’s been” since he first had problems, Zimmerman said. “But what can you do? You just got to keep working and try to get through it. It could be a lot worse.”

Meanwhile, the Nationals placed outfielder Scott Hairston on the 15-day disabled list with a left oblique strain and recalled first baseman-outfielder Tyler Moore from Class AAA Syracuse.