Jax was recalled from Triple-A St. Paul on Thursday.
Jax spent just over a week with Triple-A St. Paul, but he didn't appear in any games during his most recent stint in the minors. He'll now return to the major-league roster after right-hander Randy Dobnak (finger) was placed on the 10-day injured list. Jax's first three big-league appearances have been out of the bullpen, but he could be a candidate to start in Dobnak's absence.