The Athletics released Grimm on Tuesday.
After going unclaimed off waivers when he was designated for assignment over the weekend, Grimm will opt for free agency rather than being outrighted to Triple-A Las Vegas. Before being moved off Oakland's 40-man roster, Grimm appeared in 15 games out of the bullpen and logged a 4.11 ERA and 1.63 WHIP across 15.1 innings.