Spence struck out five over 4.2 innings of relief in Sunday's 12-3 loss to the Marlins, giving up four earned runs on six hits and one walk.
Spence (3-1) got the win against the Pirates on Tuesday, firing three scoreless, one-hit innings during which he recorded two strikeouts.
Spence (1-1) got the win over the Nationals on Sunday despite allowing two earned runs on four hits over 1.2 innings. He struck out one.
Spence (0-1) was charged with the loss in extra innings against the Red Sox on Tuesday, allowing one unearned run on one hit over one inning.
Spence is projected to open the season as part of the Athletics' bullpen, Martin Gallegos of MLB.com reports.
Spence was selected by the Athletics in the 2023 Rule 5 Draft on Wednesday.