Payamps was placed on the 15-day injured list with a strained lumbar muscle Friday.
Payamps had inconsistent results in September, posting a 5.19 ERA and 1.15 WHIP in 8.2 innings over eight appearances. Although he tossed a scoreless inning Tuesday against the Mariners, he's apparently dealing with a back issue that will force him to miss the remainder of the regular season. The right-hander made a career-high 41 relief appearances between Kansas City and Oakland this year and generated a 3.23 ERA and 1.37 WHIP in 55.2 innings.