WASHINGTON -- Max Scherzer woke up Friday morning still feeling tightness in his back, one day after he returned from the injured list to toss five innings in the Nationals' 6-5 loss to the Rockies. When the injury lingered, the Nats sent him for an MRI, which revealed a mild strain of the rhomboid muscle in his upper back, an issue that has put his next start in jeopardy.

Scherzer received a stem cell injection and will not pick up a ball for the next two days in hope that the soreness passes. Scherzer still sounded optimistic that he would be able to make his next start, which lines up for a critical game Tuesday night against the Braves.

“I’m not happy, but on the other hand, we’re talking minor strain,” Scherzer said. “So there’s a heck of a lot of other things that could be wrong with your body and arm and shoulder. Those are really, knock on wood, those are the bad stuff.

“The other good thing is that when I’m on the mound and throwing, I don’t feel any pain when I’m on the mound. Every time I play catch, I’m on the mound and throwing every ball at 100 percent.”

Scherzer did not second guess the decision to start Thursday, sticking by the fact that he felt back to full strength in the days leading up to the start, in the bullpen and on the mound for the 86 pitches he threw across five innings. He was also not quite himself in his return, allowing three runs on four hits and a pair of walks, but he also struck out eight and admitted he felt a little rusty in what was his first start in nearly three weeks.

But that this back injury won’t go away for Scherzer, who turns 35 years old on Saturday, is concerning for the Nationals, who already went a little more than two weeks without their ace earlier this month.

“We'll see how he feels in the next couple days,” manager Dave Martinez said. “We've got to be smart about this. Like I said before, we need him for the whole year. We'll see how he reacts to the shot.”

If Scherzer needs to miss a turn or more through the rotation again, Washington is short on options to replace him.

Austin Voth is on the injured list and shut down with tendinitis in his right shoulder. Joe Ross is already a part of the rotation and likely to start Saturday, leaving Erick Fedde as virtually their only other starter ready to take his place. The Trade Deadline is Wednesday, but last week general manager Mike Rizzo said he was comfortable with his team’s starting pitching depth. And the Nats are almost certain to use their resources toward acquiring a reliever instead of adding to the rotation.

However, Scherzer is still holding out hope of making his next start. He has had a stem cell shot before, on his right thumb, and did not miss a start, and he was hoping a similar situation would develop this time around. In his usual routine, Scherzer would throw a bullpen session Saturday, three days before he starts Tuesday, but he suggested he could throw a light bullpen session even as late as the day before his start and still take the mound.

Scherzer will try whatever possible to make his next start and avoid another trip to the injured list. As soon as he started feeling healthy this past Saturday, he was lobbying to Martinez to let him start Sunday. But now the Nationals will have to find a way to strike a balance between Scherzer’s desire to take the ball and keeping him healthy throughout the rest of the year.

“One, you got to understand the person, what you're dealing with,” Martinez said. “And knowing he wants to be able to help his team. But then you got to also think about his future, the future of this organization and the games he is going to pitch in come September. We're going to really need him. And that's sometimes with Max it's tough for him to understand because he's all about the now.”

“He's aggravated. I told him, let's just get you right. When you're right, you're one of the best. Let's get it right this time.”

Nats recall Barraclough; option Stevenson

The Nationals recalled reliever Kyle Barraclough from Double-A Harrisburg prior to Friday’s game against the Dodgers and optioned outfielder Andrew Stevenson to Triple-A Fresno.

Barraclough should help aid a bullpen that has been taxed in recent days and he returns after tossing scoreless outings in four of his five appearances at Harrisburg, giving up two runs in 6 2/3 innings with eight strikeouts. The Nats have nine pitchers in the bullpen.