A's righty Balfour on DL with strained oblique

The Oakland Athletics have placed right-handed reliever Grant Balfour on the 15-day disabled list because of a strained right oblique.

The move, announced before Tuesday night's game against Florida, is retroactive to June 22.

Balfour has allowed one run over his past 10 innings, a span of 10 games. He is 4-1 with a pair of saves and a 2.48 ERA.

The A's recalled right-hander Trystan Magnuson from Triple-A Sacramento to take Balfour's spot on the 25-man roster. Magnuson appeared in two games with the A's in May.