The Nationals placed left-handed starting pitcher Tom Gorzelanny on the 15-day disabled list with left elbow inflammation, which will force the Nationals to use a sixth starting pitcher for the first time this season.

Gorzelanny, who is 2-4 with a 4.25 with 48 strikeouts and 20 walks in 53 innings, last pitched Monday during an 11-3 loss to the Milwaukee Brewers. He made no mention of any arm trouble, but he did express concern over locating too many waist-high, which led to an unusually high number of homers for him — he has allowed 11 home runs this year in nine starts.

Gorzelanny had been scheduled to start Sunday for the Nationals. Since the Nationals had a day off Thursday, they could choose to continue throwing starters on normal rest until Tuesday, moving Livan Hernandez up to Sunday and Jason Marquis to Monday.

In Class AAA Syracuse, the Nationals have several candidates with major league experience to take Gorzelanny’s spot in Ross Detwiler (3-4, 5.77 ERA at Class AAA), Craig Stammen (4-2, 3.62) and Yunesky Maya (1-4, 3.79), all of whom are on the Nationals’ 40-man roster.

If the Nationals simply chose the pitcher who lines up to pitch on normal rest Tuesday, they could choose to promote Tom Milone, their 2010 minor league pitcher of the year, who is not on their 40-man roster. The Nationals, though, would have some options to make room on the 40-man, including placing Chad Gaudin on the 60-day disabled list.

The fifth current Syracuse starter, Brad Meyers, could also be a viable candidate even though he is not on the 40-man roster. Meyers has a jaw-dropping 57:1 strikeout-to-walk ratio in 10 starts, six at Class AA Harrisburg and four with Syracuse.

One side effect: The Nationals will likely promote Brad Peacock, one of their top pitching prospects, from Harrisburg to Syracuse. Peacock is 7-1 with a 2.13 ERA and 75 strikeouts and 10 walks in 55 innings this season. Friday afternoon, Nationals director of player development Doug Harris said Peacock had “put himself in a position” to earn a promotion when the opportunity arrived.