WASHINGTON – The Washington Nationals placed outfielder Austin Kearns on the 15-day disabled list Tuesday with to a stress fracture in his left foot and reinstated outfielder Elijah Dukes.

It marked the 25th time the Nationals have sent a player to the DL this season. It is the second stint for Kearns, who missed 38 games earlier this season after having loose bodies removed from his right elbow.

General manager Jim Bowden said Kearns is expected to miss four to six weeks.

Kearns had been playing with the injury for most of August. An MRI on Monday revealed the stress fracture.

“No injury on our roster surprises me anymore,” manager Manny Acta said. “He's a tough guy. He plays through pain and all that, but we thought this was the best thing for him and our club.”

Dukes, recalled after Tuesday night's 2-1 victory over the Los Angeles Dodgers, missed 19 games on the 15-day DL with a strained right calf. He went 1-for-11 with a home run and three walks in six games during a rehab assignment with Triple-A Columbus.

Dukes is batting .264 with six home runs and 23 RBIs for the Nationals. He has missed a combined 72 games during three stints on the disabled list this season.

Kearns isn't exactly sure when his injury occurred. Acta and Bowden both pointed to a game Aug. 3, when Kearns fouled a ball off his foot, as the likely culprit.

“I think it was probably some buildup over time,” Kearns said. “I don't know if it was exactly one thing.”

Kearns' foot will be put into a walking boot for the next two weeks, and then the team will be better able to evaluate exactly how much time he will miss.

“We'll see how he is,” Bowden said. “Of course, Austin wants to play, but it's not going to get better.”

Kearns is batting .217 with seven home runs and 32 RBIs.

AP freelance writer Daimon Eklund contributed to this report.