JUST IN: Oli Marmol announced his reason toward this veteran starter for…..

The manager of the Cardinals, Oli Marmol, announced yesterday that left-hander Matthew Liberatore will start for the team against the Red Sox tomorrow. He also told reporters, including Jeff Jones of the Belleville News-Democrat, that Liberatore will stay in the rotation “for now” while the team deals with Steven Matz’s injury, which is related to a strained lower back.

Following a challenging start against the Angels earlier this week in which he gave up four runs on five hits, two walks, and one strikeout in 3 1/3 innings of work, Liberatore now has further news. The lefty threw a career-high sixty pitches during the appearance and, considering that he was moved from short relief in the bullpen to a starting role with little time to warm up, looks likely to be equally constrained against Boston tomorrow. Prior to entering the rotation, Liberatore was one of the team’s most valuable relievers, pitching to a 2.76 ERA in 16 1/3 innings pitched, despite a dismal 16.4% strikeout percentage.

The choice to keep Liberatore as the fifth man in the rotation is a little perplexing given his low pitch total, difficulties in the rotation, and success this year out of the bullpen. The team has a ton of options to choose from when it comes to filling the 40-man roster in Triple-A: In the beginning of the season, right-hander Andre Pallante has shown promise in the minor leagues and has plenty of experience swinging between the rotation and the bullpen. Meanwhile, left-hander Zack Thompson relieved Sonny Gray in the rotation, but with mixed results of his own. The club acquired right-handed prospect Sem Robberse in the Jordan Hicks trade last summer, and he has made eight starts at Triple-A with a 2.64 ERA and 4.05 FIP. Robberse is off to an outstanding start as well. If Liberatore’s difficulties in the rotation persist, any one of those choices could take his spot in the starting five.

Although Liberatore’s addition to the rotation has eliminated a reliable relief option for the Cardinals, it looks as though more help is on the way as both Keynan Middleton and veteran right-hander Giovanny Gallegos are making progress toward returning from the injured list. Middleton looks to be progressing more quickly than the two veterans, according to Jones, who reports that he will make three more rehab appearances in the next few days, including back-to-back starts on Tuesday and Wednesday, before the team decides if he’s ready to rejoin the major league bullpen.

Middleton might make his Cardinals debut by the end of the week under that plan despite missing the season’s opening game because of a strain in the forearm. Throughout his 50 2/3 innings thrown between the White Sox and the Yankees last season, the right-hander recorded a 3.38 ERA and 4.20 FIP. He was particularly impressive during a 14 1/3 inning span in New York, where he struck out 30.4% of batters faced and allowed just three runs. When Middleton returns, he should be considered for late-inning opportunities with players like Andrew Kittredge, JoJo Romero, and Ryan Helsley.

Gallegos, on the other hand, is expected to make a quick recovery after being sidelined earlier this month because of a shoulder impingement. Gallegos is feeling better and threw a bullpen yesterday, according to MLB.com’s John Denton, who reported this afternoon. However, Marmol claims that is still strengthening his arms in preparation for a comeback to major league baseball. Denton said that Gallegos is slated to go on a rehab assignment to the minor levels in the next few days, so it looks like he’ll keep doing that.