Manager Carlos Mendoza confirmed Wednesday that McLean will be called up from Triple-A Syracuse to start Saturday's game against the Mariners at Citi Field, Laura Albanese of Newsday reports.

One of the Mets' top pitching prospects, the 24-year-old McLean has delivered a 2.45 ERA, 1.13 WHIP and 127:50 K:BB across 113.2 innings between Syracuse and Double-A Binghamton this season. The Mets will likely wait until Saturday before formally adding McLean to the 40-man roster and 26-man active roster. With Frankie Montas moving to the bullpen and Paul Blackburn (shoulder) also expected to work in long relief following his activation from the 15-day injured list Wednesday, McLean could be in line for multiple turns through the rotation until the Mets get Tylor Megill (elbow) back from the IL.

The Mets optioned Hagenman to Triple-A Syracuse on Wednesday, Andy Martino of SNY.tv reports.

Hagenman pitched in three games since his latest recall but will head back to the minors after the Mets activated Paul Blackburn (shoulder) from the 15-day IL on Wednesday. Hagenman has a 3.26 ERA, 0.93 WHIP and 20:2 K:BB across 19.1 innings for New York this season, so he could get another look with the big club down the stretch.

The Diamondbacks recalled Kelly from Triple-A Reno on Wednesday, Alex Weiner of ArizonaSports.com reports.

Arizona had optioned Kelly to Triple-A on Saturday after he made a pair of relief appearances following his promotion from the minors, but he'll be eligible to rejoin the big club after starter Anthony DeSclafani (thumb) was placed on the 15-day injured list in a corresponding move. DeSclafani's next turn through the rotation is scheduled to come up Sunday in Colorado, and Arizona could turn to Kelly to make a start if he's not needed in relief over the team's next four contests. Kelly had operated primarily as a starter at Reno this season, accruing a 5.82 ERA, 1.71 WHIP and 42:33 K:BB across 85 innings.

The Diamondbacks placed DeSclafani on the 15-day injured list Wednesday due to right thumb inflammation, Alex Weiner of ArizonaSports.com reports.

Arizona recalled right-hander Casey Kelly from Triple-A Reno in a corresponding move, and if he's not needed in relief over the next four days, he could end up taking DeSclafani's spot in the rotation the next time it comes up Sunday in Colorado. DeSclafani initially worked in relief after joining the Diamondbacks in mid-June, but he had started in his last three appearances and logged a 5.99 ERA, 1.66 WHIP and 7:5 K:BB in 9.2 innings during that stretch.

The Reds optioned Benschoter to Triple-A Louisville on Wednesday.

Benschoter will head back down to the minors after the Reds activated Hunter Greene (groin) from the 15-day IL on Wednesday. Benschoter has yet to make his MLB debut, as he didn't appear in a game during either of his two short stints on the 26-man roster this season. He owns a 3.78 ERA and 7.7 K/9 across 104 innings at Triple-A.

The Tigers optioned Heuer to Triple-A Toledo on Wednesday, Evan Petzold of the Detroit Free Press reports.

Heuer has permitted three runs over 4.2 innings covering three relief outings between the Rangers and Tigers this season. He's being replaced on the roster by Sawyer Gipson-Long, who is back from the injured list.

The Tigers activate Gipson-Long (neck) from the 15-day injured list Wednesday, Evan Petzold of the Detroit Free Press reports.

Gipson-Long has been shelved since mid-July with a neck injury and had to be pulled off his initial rehab assignment due to continued stiffness. However, he's ready to go now after allowing two runs across 7.1 frames in two rehab appearances this month. Gipson-Long appears slated for a long-relief role for the time being.

The Mets are expected to call up McLean from Triple-A Syracuse to start Saturday's game against the Mariners, Andy Martino of SNY.tv reports.

With manager Carlos Mendoza permanently moving Frankie Montas to the bullpen, the Mets will need to break in a new fifth starter this weekend. Though veteran righty Paul Blackburn (shoulder) has been building up a starter during his rehab assignment and looks ready to come off the 15-day injured list, the Mets instead appear inclined to give the 24-year-old McLean his first look in the big leagues. The right-hander has made 21 appearances (18 starts) between Double-A Binghamton and Triple-A this season, registering a 2.45 ERA and 1.13 WHIP while racking up 127 punchouts over 113.2 innings. The Mets could get Tylor Megill (elbow) back from the injured list by the end of the month to challenge him for a rotation spot, but if McLean impresses in his initial taste of the majors, he could end up holding down a starting role for the rest of the season.

The White Sox designated Shuster for assignment Wednesday.

The transaction frees up a spot on the 40-man roster for left-hander Martin Perez (elbow), who was activated from the 60-day injured list. Shuster has collected a 5.27 ERA over 62 career appearances (17 starts) at the big-league level.

The White Sox optioned Booser to Triple-A Charlotte on Wednesday.

Booser made a pair of scoreless appearances during his most recent stint in the big leagues, but he will nonetheless be dispatched back to the minors. The lefty reliever holds a 4.85 ERA and 29:14 K:BB over 26 innings this season.