Updated at 6:18 p.m.
CINCINNATI -- Luis Atilano, who hasn't produced a quality start in nearly a month, is "unlikely" to make his next scheduled start due to an arm issue according to manager Jim Riggleman.
Riggleman said the rookie right-hander, who allowed five runs in four innings last night, appears to be dealing with some kind of discomfort. It's not known whether it's from an injury or a "dead arm;" Atilano hasn't undergone an MRI at this point.
"After the game last night, [pitching coach] Steve McCatty said he just felt that Atilano was not feeling well," Riggleman said. "His arm was tender, and this and that. Whether or not he makes his next start will be after further conversation with him and watching him throw out here today, to see if he's firing the ball around or if he says 'my arm is dead' or if he's just got a tired arm."
Riggleman said Atilano will throw his regular between-starts bullpen session tomorrow, after which the club will make a decision. Atilano is slated to pitch Sunday in Milwaukee. If he can't go, the Nationals would have to find a starter in the minors. Ross Detwiler, the strongest candidate for a promotion, probably wouldn't be available because he tossed seven shutout innings today for Class AA Harrisburg and would have to come back on short rest.
Matt Chico, who pitched last night for Class AAA Syracuse and would line up perfectly to start on Sunday, hasn't allowed a run in his last two starts. John Lannan last pitched Saturday for Harrisburg; in five overall starts, he's 1-2 with a 4.11 ERA.
Atilano, meanwhile, has been in a prolonged funk. Over his last four starts -- including one appearance at Syracuse during the All-Star break -- he's allowed 19 earned runs and 24 hits in 15 1/3 innings.
"His last one or two before he went to Syracuse were not as sharp as he had been," Riggleman said. "His outing in Syracuse wasn't sharp. And then yesterday he wasn't sharp. So we've got to be open to anything."