Jax will be called up to start Friday against the Cardinals.
Jose Berrios had been the team's scheduled starter but was instead traded to Toronto. Jax has made two starts and four relief appearances at the big-league level this season but hasn't shown much, struggling to a 7.48 ERA and 1.48 WHIP. Still, the fact that he's getting the first opportunity in Berrios' absence could indicate that he'll have an inside track at a starting role down the stretch, which could make him worth keeping an eye on in deep leagues.