"(It didn't happen) on any particular pitch, nothing involving the elbow, but took him out after his first inning as a precaution," Williams said. "He'll see the doc in Washington tomorrow. We'll evaluate from there. "We'll see what the doc says. It's a little early to tell right now. But we'll get the report tomorrow and see where we're at." Nationals pitching coach Steve McCatty stayed back in Viera to watch Fister's outing, and said that the right-hander complained of some tightness in the lat before he even took the mound. McCatty said that Fister hasn't complained about any lat issues prior to today, but that the discomfort didn't dissipate after the one inning of work. "He said, 'Yeah, I felt a little something in there,' " McCatty said. "I said, 'I really don't want to do this, but if you feel something in there ... is it something you can pitch (with)? I really would like to shut this off.' He shook his head and agreed. He felt a little tugging in there. So we stopped. ... "You've got to be cautious about something like this. He threw 15 pitches. He had 45 left. I was not going to let him attempt to get through. If I told him he was all right to go, he probably would have went out there. You've got to be smart in those situations." The typical progression for pitchers building up to regular season action is that they increase their workload by about 15 pitches each time out. Fister threw 47 pitches Saturday in a game against the Marlins, and the Nats had hoped to get him over 60 pitches today, and then into the 75-pitch range in his next minor league start. Even if Fister comes through with this lat issue not being anything major, he'll be set back as he tries to build up arm strength. He would likely need to prove that he could handle a 75-pitch workload before being cleared to pitch in a regular season game. "So it certainly is a setback," Williams said. Unless Fister is able to quickly recover and build up enough arm strength to make his first regular season start - the Nats had targeted April 6 against the Braves, the first time that they need a fifth starter - then the Nats will end up with both Tanner Roark and Taylor Jordan in their opening day rotation. Those two right-handers had been competing for the final spot in the Nats' starting staff, but they might both end up a part of the rotation with Fister's latest setback. "They both earned the right to pitch," Williams said. "We'll have to see. We'll have to see how (Fister) feels tomorrow, what the doctor says, where we're at. But right now we just know he couldn't make it through his start today."