Coulombe had his contract selected by Oakland on Tuesday.
Coulombe began the season at Triple-A and was off of the 40-man roster, but he'll now be added to the roster while making his first trip up to the big leagues this season. The move comes on the heels of the A's sending Liam Hendriks (arm) to the DL and optioning J.B. Wendelken to Triple-A on Tuesday. Coulombe has fared well at Triple-A this season, appearing in 11 games and allowing just one earned run on six hits (14.0 innings).