Costeiu (elbow) has given up two earned runs on one hit and five walks while striking out five over 6.1 innings in two appearances for High-A Tri-City since returning from the 7-day injured list May 14.
Costeiu missed the first month of the minor-league season while completing his recovery from right elbow surgery. The 23-year-old right-hander made one rehab appearance in the rookie-level Arizona Complex League on May 6 before he was advanced to the Northwest League.