Right-hander Spencer Turnbull has been a revelation in the Phillies’ rotation after filling in for the injured Taijuan Walker to begin the season. While Walker’s return from the injured list might have seemed like an obvious means of pushing Turnbull back into a long relief role earlier in the season, Turnbull has pitched so well that the Phils likely feel they can’t take him out of his current spot.

Indeed, manager Rob Thomson told the Phillies beat yesterday that the club will consider creative means of keeping Turnbull in the mix — be it piggybacking him with another starter or alternating between Sanchez and Turnbull in the fifth spot of the rotation depending on the opponent they’re facing (links via Corey Seidman of NBC Sports Philadelphia and Todd Zolecki of MLB.com).

The Phillies’ rotation, as a whole, has been remarkable this season. Philadelphia starters rank first in the majors with 190 2/3 innings pitched, second with a 2.50 ERA, second with a 26% strikeout rate, tenth with a 7% walk rate and third with a 52% ground-ball rate. Their collective 3.28 FIP is also second-best in MLB, and Phillies starters lead the league with a 3.22 SIERA. By virtually any measure, they’ve been outstanding.

Righties Zack Wheeler and Aaron Nola are both out to excellent starts. Wheeler, in particular, is sitting on a sub-2.00 ERA with his typical blend of plus strikeout, walk and ground-ball rates. Nola is sporting a 3.20 mark with a roughly average strikeout rate and a strong 7% walk rate. He’s been a bit homer-prone for what’s now a second straight season, but he’s generally pitched well in the first season of his new seven-year contract.

Left-hander Ranger Suarez has arguably been the team’s most effective starter. He touts a team-best 1.32 ERA through his first six turns on the mound. He’s logged 41 innings with a plus 27.8% strikeout rate and elite walk and ground-ball rates (3.5% and 60.8%, respectively). He won’t sustain a .189 BABIP and 92.9% strand rate, but the skill components of his performance have been terrific.

Fifth starter Cristopher Sanchez has been solid, recording a 3.68 ERA in 29 1/3 frames. His 22% strikeout rate is barely south of average, and while his 9.8% walk rate is on the high side, he’s helped mitigate some of those free passes with a massive 62.2% grounder rate. Righty Taijuan Walker just returned from the injured list and was hit hard in his first start, but he was a quality innings eater for the Phils last year (4.32 ERA in 31 starts) and is being paid $18MM this season to fill that role again.

Turnbull’s run-prevention thus far is right up there with Wheeler and Suarez. Through six starts, he’s pitched 32 1/3 innings of 1.67 ERA ball with an excellent 28.7% strikeout rate against a 7.9% walk rate that’s about a percentage point better than average. He’s not sitting at Suarez/Sanchez levels with his ground-ball rate, but his mark of 49.4% is still comfortably north of the 43% league average.

A piggyback situation with Sanchez or some kind of alternating fifth starter role could make particular sense for Turnbull, who missed  the 2022 season recovering from Tommy John surgery and pitched only 57 innings between the big leagues and minors last year. At some point, his workload could become a factor, as his body simply hasn’t endured a full season of innings since the 2019 campaign, when he started 30 games for the Tigers and pitched 148 1/3 innings.

The more straightforward solution would be to go to a six-man rotation, but Thomson has suggested in the past that the team doesn’t consider that a likely arrangement. However they proceed, it seems Turnbull — who has already wildly outperformed his modest one-year, $2MM deal — will continue to factor prominently into the team’s pitching staff as he gears up for what seems likely to be a much more lucrative trip through free agency again next winter.