The Reds will activate right-hander Josh Fogg from the disabled list to start against the Washington Nationals, manager Dusty Baker said Friday.

Harang, the Reds opening day starter, is 1-4 with a 6.75 ERA in seven starts since he pitched four innings of relief in Cincinnati's 12-9, 18-inning loss at San Diego on May 25. He was roughed up for 10 hits and six runs in four innings in his next game, a start against Pittsburgh on three days of rest instead of his usual four.

"He has stiffness in his forearm muscle, like he had two years ago when was skipped in the rotation," Baker said.

The right-hander is 3-10 with a 4.47 ERA in 19 games. He is scheduled to start Tuesday against the Cubs in Chicago.

Fogg, 1-2 with a 9.85 ERA in 11 games, including four starts, has been on the disabled list since June 1 with back problems.

To make room on the roster for Fogg, Cincinnati will put outfielder Norris Hopper on the disabled list. Limited to 26 games by elbow problems, Hopper will undergo ligament replacement surgery on his elbow Tuesday, Baker said.

"You could see it in his throws, and he couldn't extend his elbow when he was hitting," Baker said.

Hopper was on the disabled list from April 23 to June 18.