Stephen Strasburg unable to make Friday's start

ST. LOUIS - Stephen Strasburg will not make his scheduled start on Friday against the Braves at Nationals Park. Manager Matt Williams announced before tonight's game that right-hander Tanner Roark will be recalled from Double-A Harrisburg to fill Strasburg's spot.

Strasburg left Sunday's 7-4 win over the Marlins after just four innings with upper back tightness.

Williams indicated that Strasburg reported today feeling good after throwing on flat ground yesterday. He threw again on the field at Busch Stadium this afternoon.

According to Williams, Strasburg could potentially re-enter the rotation without missing a full turn.

"It's possible," Williams said. "We'll have to see how he does, though. We'll get him a fairly heavy bullpen (tomorrow), which will take him another two days after that, at least. We'll see. We gotta get him off that slope and make sure he feels good letting it go. There's no use pushing him through something that would potentially hurt him."

The back discomfort initially bothered Strasburg during a start on May 5, knocking out the 27-year-old after only three innings. He ended up on the 15-day disabled list on May 30 with neck tightness.

Strasburg returned to the mound for the Nationals on June 23, appearing comfortable and confident over two starts until a strained left oblique derailed his outing against the Giants on July 4. He ended up back on the DL for over a month, but came back showing dominant form.

Strasburg was 3-1 with a 1.73 ERA in four starts before the back tightness flared up. In Sunday's outing, Strasburg was tagged for four runs, including two homers.

Roark was optioned to Single-A Potomac on August 25 so he could prepare to potentially return to the rotation in the event that rookie Joe Ross had to be shut down for reaching an innings limit.

Roark made one start for Potomac and another at Double-A Harrisburg, yielding one run on five hits with seven strikeouts and no walks over seven innings.

Despite working primarily out of the bullpen, Roark made six starts for the Nationals this season, going 3-1 with a 5.61 ERA. He was one of the most reliable starters for the Nats in 2014, spinning a 15-10 record with a 2.85 ERA in 31 starts.