Tanner Bibee hit Charlie Blackmon with a 1-2 fastball to lead off his MLB debut on Wednesday, but retired the next three batters — including two on pop outs — to escape the first inning unscathed. The Guardians right-hander got into a groove when he struck out the side in the next two frames, going on to finish with 8 Ks in 5 1/3 innings to earn the win against the Rockies.

The 24-year-old threw 91 pitches, 60 for strikes, and didn’t walk a batter. Five of his strikeouts came on his nasty slider.

Bibee was assigned to Triple-A coming out of spring training and along with fellow blue-chip pitching prospects Logan Allen and Gavin Williams provided other options for the Cleveland rotation should any openings develop. It didn’t take long, as Triston McKenzie was placed on the injured list with a shoulder strain on March 30 and Aaron Civale joined him there on April 10 with an oblique strain. The Guardians first turned to lesser prospects Hunter Gaddis and Peyton Battenfield before going to Allen on Monday and Bibee on Wednesday.

With both Bibee and Allen looking good in their debuts, they are expected to stay in the rotation for now. McKenzie is eligible to come off the IL on May 29, which is about when Civale might be nearing a return, so the youngsters should have a month to prove themselves worthy of staying in Cleveland even after the veterans are back.

After not being selected in the abbreviated five-round draft of 2020, Bibee went to the pitching lab at Driveline Baseball in Kent, Wash., to add velocity. When he came back for his senior season at Cal State Fullerton, Bibee had gone from throwing his fastball in the upper-80s to sitting in the low-90s and touching 95 mph. The Guardians took notice and popped him in the fifth round in the 2021 draft, then went to work on the 6-foot-2, 205-pounder with their own pitching wizards. By the time he made his pro debut in 2022 for High-A Lake County, Bibee was throwing in the mid-90s and mowed down Midwest League batters for a 2.59 ERA with a whopping 86-to-13 strikeout-to-walk ratio in 59 innings. He kept it up for Double-A Akron, posting a 1.83 ERA with a 81-14 K-BB in 73 2/3 innings to finish the season.

Starting this season for Triple-A Columbus, Bibee was sitting 94-97 mph with his fastball, touching 99.4 in a start earlier this month. In three starts for Columbus, Bibee had a 1.76 ERA with a 19-8 K-BB in 15 1/3 innings.

So what can we expect from the Mission Viejo High School grad in his rookie season? The projection systems seem to be missing the boat with Bibee — Steamer has him just getting 39 innings with a 4.42 ERA. We’re certainly worried about the innings too, but if Bibee continues to look anything like he did on Wednesday, it’s not hard to imagine the rookie staying in the rotation over Zach Plesac, Cal Quantrill or Civale. Even if he spends some time back in Triple-A, Bibee could approach 100 innings for Cleveland, so; something like a 3.75 ERA with a 1.18 WHIP and 110 strikeouts is a reasonable expectation.

The worry is that the Guardians choose to spread out their innings across their plethora of pitching options, from the aforementioned veterans to their slew of prospects, and Bibee winds up only being used sparingly in the majors this season.

As for the long-term future, Bibee looks capable of following the same path that Shane Bieber has taken, as an unheralded college pitcher whose stuff ticks up under Guardians tutelage then uses his elite command to become a staff anchor in Cleveland for the next decade. With career minor-league rates of 11.3 K/9 and 2.1 BB/9, Bibee has the ceiling of a fantasy ace and has the floor of a mid-rotation starter if he can stay healthy.