It’s no surprise that the Cleveland Indians have had one of the best starting rotations in baseball this year. Last season, four of their starters eclipsed the 200-strikeout mark, the first time in history that had happened, and all four seemed primed for another big year. Some observers even labeled them the best group in the sport.

Cleveland’s starters have indeed been outstanding — tied for the fourth-lowest E.R.A. in the majors — but they have done it with a much different group than anyone expected. By midseason, only one of the four who surpassed 200 strikeouts last year, Mike Clevinger, remained on the active roster, the other three gone to injuries or trades.

But all that did was pave the way for three new faces who have risen through the Indians’ ranks together and have now helped carry the club to the brink of a playoff berth. Three years after they were all selected in the same draft, the trio of 24-year-olds — Shane Bieber, Aaron Civale and Zach Plesac — are part of the youngest rotation in the American League.

“Seeing guys that I got drafted with in the same rotation as me is crazy,” Plesac said. “I don’t know if any of us would have seen it happening like that. Us working together and seeing each other all in the same place gives us a feeling that we are in it together.”