The right-handed reliever made his season debut in Detroit's 8-7 loss in 10 innings to the White Sox on Thursday afternoon in a high-pressure situation during the seventh inning, summoned out of the bullpen to face Jose Abreu and Adam LaRoche with one out and runners on first and second.
But Rondon -- who missed 2014 as he recovered from Tommy John surgery and had been on the disabled list with right shoulder tendinitis -- needed just eight pitches to work himself out of the jam. He struck out Abreu swinging on an 87-mph slider, then turned up the heat to strike out LaRoche with three straight fastballs.
The final one, which froze Chicago's designated hitter, clocked in at 101 mph.
"He did nice," said Tigers manager Brad Ausmus. "Came in and got the two big outs. Felt like he had a good two-thirds of an inning the first time back, and just go ahead and get him out of there. Maybe get him rolling from that point on."
A healthy and effective Rondon could be a major boost for Detroit's bullpen, which entered Thursday with a 3.67 ERA and was allowing opponents to hit at a .261 clip -- fifth-highest in baseball.
Rondon had a 10.38 ERA in nine appearances with Triple-A Toledo before the club activated him and optioned him to the Mud Hens on June 15. He didn't allow a run to score in his next four appearances and was recalled by the Tigers before Thursday's series opener.
"He's gotta work himself into a role if there's going to be one," Ausmus said prior to the game. "Otherwise, we'll use him out of the 'pen when we think we need him."
Thursday was an encouraging indication of what he could contribute.
Alejandro Zúñiga is an associate reporter for MLB.com. Follow him on Twitter @ByAZuniga.