Josh Johnson is done for the season because of a strained right forearm.

Johnson, who hasn't pitched since Aug. 6, won't require surgery.

"We expected a lot, he expected a lot -- it just didn't happen," John Gibbons said of Johnson's disappointing season. "He had the best spring of our staff; he looked better than most guys we faced on other teams. Who knows [why it didn't work]? Nobody knows."

Johnson made just 16 starts and had an ugly 6.20 ERA in 2013.