Why didn't Phillies make this rotation move sooner?

The Philadelphia Phillies were outscored 32-12 in their final three games after winning 10 of their last 12 to end the month of May.

Entering June, the club has decided to shake up its rotation and bullpen. Mick Abel, who made his MLB debut on May 18, will be recalled from Triple-A before the Phillies' series vs. the Blue Jays in Toronto on Tuesday.

In his debut, Abel outdueled Pittsburgh Pirates ace Paul Skenes, throwing six shutout innings, allowing five hits and striking out nine. However, following the game, Abel was optioned to the minors, and Philadelphia inserted Taijuan Walker back into the rotation.

Abel's debut was scheduled to be a spot start, but he pitched so well that fans believed he could stick with the club for the time being, especially considering that Walker looked good during his minimal time in the bullpen.

As a starter, Walker pitched to a 3.62 ERA in 37.1 innings, walking 16 and striking out 30. In six innings out of the bullpen, he had a 3.00 ERA with nine Ks and one walk. The team initially planned to have Walker as a long relief arm, but now they're shifting him to a leverage role, per the Philadelphia Inquirer's Scott Lauber.

This is expected to be a permanent move, at least until Aaron Nola returns from the injured list.

Why the Phillies didn't make this move following Abel's promising start is puzzling. They're already short on bullpen depth as it is after Jose Alvarado was suspended for 80 games and Jose Ruiz was designated for assignment on Sunday. Plus, they have the sixth-worst bullpen ERA in the league at 4.68. They need all the help they can get.

Philadelphia also recalled right-hander Seth Johnson from Triple-A on Sunday, so he offers them another relief option. The 26-year-old has a career 3.09 ERA in the minor leagues.

Since debuting, Abel continued his strong season, fanning 16 batters and allowing just one run in 8.2 innings across two starts. The Phillies hope he can keep up this success and help them get back on track as June begins.