BALTIMORE -- Chris Tillman was placed on the 15-day disabled list by the Baltimore Orioles on Wednesday due to right shoulder inflammation.
The move was expected. Tillman threw a bullpen session Tuesday, but he complained of continued shoulder discomfort, and manager Buck Showalter said afterward that a DL trip was likely.
Tillman's previous start also had been pushed back to this past Saturday due to the shoulder, and he ended up lasting just two innings in a loss to the Houston Astros.
Tillman, 28, had been slated to take the hill on Thursday against the Nats and ace Max Scherzer in the finale of the teams' four-game series.
"It's tough," Tillman, who has made at least 30 starts in each of his three full seasons in the Orioles' rotation, said Wednesday. "I don't like it, but it is what it is. It happened, and we've got to get better now. I think this is the best way to go about it, and we had talked about it a little. I'd rather feel better at the end of the season, rather than fighting it all year."
On the season, Tillman is 15-5 with a 3.76 ERA as the ace of a rotation. No other Baltimore starter has won more than five games this season.
The Orioles, who entered Wednesday in possession of the second AL wild-card spot, are 20-6 in games started by Tillman and 49-50 in all others.
Ubaldo Jimenez will take Tillman's place in the rotation Thursday. Though he is 5-10 with a 6.94 ERA this year for Baltimore, Jimenez's numbers against the Nats are much better. He is 6-1 with a 2.32 ERA in eight career starts against Washington.
In a corresponding roster move, Baltimore recalled right-hander Mike Wright from Triple-A Norfolk.
Information from ESPN's Eddie Matz was used in this report.