CLEVELAND -- The Indians wanted to experiment with the option of using starter Triston McKenzie out of the bullpen before the postseason got underway. If his performance in Wednesday night's walk-off victory over the White Sox was any indication of what's to come, he certainly passed the test.

After starter Shane Bieber's pitch count reached 98 through five innings, the Indians turned to McKenzie to start the sixth. In two frames, the 23-year-old did not permit a run and held the White Sox to one hit with three strikeouts.

“That's the first time I've ever come out of the 'pen,” said McKenzie, ranked as the Indians' No. 10 prospect by MLB Pipeline. “It was more just coming out, knowing the situation of the game, attacking the hitters and trusting the guys around me.”

The biggest sign of encouragement was McKenzie's fastball velocity. The average speed of his heater had dropped to 90.2 mph in his sixth and most recent start. Because he had gone two years since pitching in any game-like setting due to injuries before he was called up to the big leagues in August, the Indians were not concerned about fatigue but thought he could thrive more in a relief role. On Wednesday, his velocity shot back up to an average of 93.9 mph, topping out at 95.

“McKenzie slid right in,” temporary Indians manager Sandy Alomar Jr. said. “[He] was throwing 94-95 [mph] with a good wipeout breaking ball. That's a good option for us in the 'pen. Pretty excited to see that.”

The Tribe will need only two or three starters in the best-of-three Wild Card Series, so McKenzie's move to the bullpen was a strategic decision. But now that he's proven he can be a threat in relief, that could be a tremendous benefit for Cleveland, especially if a starter fails to complete six innings. Should the Indians advance beyond the first round to a longer series, the team would then consider adding McKenzie back in the rotation or leaving him in the ‘pen.

“We were kind of excited about [getting him in the game],” Alomar said. “Kind of anxious about it because you want to see what kind of options you have in the postseason if Triston was to be used, and that was a positive outing for him yesterday. His velo went up, great breaking ball, and he was able to be under control. I know this is not the postseason, but to get to the postseason, you have to get the experience here now. So, at least we got him in there and he performed well.”

Round 1 rotation
One thing is for sure: Bieber will get the ball on Tuesday in Game 1 against whichever opponent the Indians draw for the Wild Card Series. From there, decisions are still being ironed out. Alomar said that it's likely the two other starters will be Zach Plesac and Carlos Carrasco, but who pitches Game 2 and a potential Game 3 is still being determined.

• What comes next? Indians postseason FAQ

The way Plesac and Carrasco finish out the year in their final starts on Thursday and Friday, respectively, could play into the decision. Carrasco has gotten into a groove over his past five starts, with a 1.41 ERA in that span. But Plesac has had a strong sophomore campaign, showing tremendous growth and command of the strike zone.

“That's phenomenal development,” Alomar said of Plesac. “You have to give credit to the organization for helping him through the process. Plesac kind of revamped a little bit of his delivery. … But the command is what really impressed me the most. The changeup command, the separation between those two pitches and the breaking ball. He has a special breaking ball.”