The Royals recalled Zerpa from Triple-A Omaha on Saturday.

With Chris Stratton (forearm) headed for the injured list, the Royals will call upon Zerpa to help get their bullpen through the final couple weeks of the regular season. The 24-year-old southpaw owns a 4.40 ERA and 1.57 WHIP through 47 big-league innings on the year and will most likely serve in middle relief while with Kansas City.

The Royals placed Stratton on the 15-day injured list Saturday with a right forearm flexor strain.

Stratton surrendered two earned runs over an inning out of the bullpen Friday, but he appears to have come away from his latest outing with an injury. He won't be eligible to return from the IL until the final game of the season Sept. 29, and it's possible the Royals elect to keep him on the shelf until the start of the postseason, assuming they hang onto their wild-card spot. Until then, Angel Zerpa will come up from the minors to fill the opening in Kansas City's bullpen.

The Red Sox optioned Booser to Triple-A Worcester on Saturday, Julian McWilliams of The Boston Globe reports.

After surrendering two earned runs over one-third of an inning during Friday's loss to the Yankees, Booser will be sent back to Triple-A alongside Zack Kelly in order to clear room in Boston's bullpen for fresh arms Bailey Horn and Zach Penrod.

The Red Sox optioned Kelly to Triple-A Worcester on Saturday, Julian McWilliams of The Boston Globe reports.

Kelly gave up three earned runs without recording an out during Friday's loss to the Yankees, inflating his ERA to 3.97 across 56.2 innings. He'll now head back to Triple-A, though there's still a possibility he makes another appearance in the majors before the season ends. He'll be joined in Worcester by Cam Booser while Bailey Horn and Zach Penrod come up from the minors to fill the open bullpen spots.

The Red Sox recalled Horn from Triple-A Worcester on Saturday, Julian McWilliams of The Boston Globe reports.

Horn has allowed just one earned run over 5.1 innings since being optioned to Triple-A in late August, and he'll now be called upon to give the Red Sox a fresh arm out of the bullpen. Zach Penrod will make the journey to Boston alongside Horn, forcing Zack Kelly and Cam Booser back to the minors.

Sborz (shoulder), who began a rehab assignment Aug. 24, restarted his assignment this week after taking an extended break, MLB.com reports.

Sborz made two appearances in four days before shutting it down in August. This week, he threw a scoreless inning Tuesday, and then allowed two runs on a hit and two walks in two-thirds of an inning Friday. When healthy, Sborz has delivered a 3.38 ERA over 16 relief innings, but his current stint on the IL is his third due to shoulder-related issues.

Burke is listed as the White Sox's probable starting pitcher for Sunday's game against the Athletics in Chicago.

He'll fill the vacant fifth spot in the White Sox rotation after Nick Nastrini was optioned to Triple-A Charlotte earlier this week. Burke was called up from Triple-A in a corresponding move and made his MLB debut out of the bullpen Tuesday against Cleveland, striking out three while allowing an unearned run on three hits and one walk over three innings. He was a full-time starter for Charlotte prior to his promotion, pitching to a 4.62 ERA, 1.29 WHIP and 86:36 K:BB in 64.1 innings.

Garabito has made his last two appearances out of the bullpen, giving up two earned runs on one hit and one walk while retiring two batters via strikeout in outings Tuesday in Arizona and Thursday in Seattle.

Since tossing 2.2 scoreless innings to lead off a bullpen game for the Rangers last Friday versus the Angels, Garabito has shifted back to a relief role. With Texas getting Jacob deGrom back from the 60-day injured list Friday and Max Scherzer (shoulder) due to return from the 15-day IL on Saturday, the Rangers aren't expected to have an opening in the rotation for Garabito for the remainder of the season.

Munoz struck out one in a perfect inning to earn the save in Friday's 5-4 win over the Rangers.

Munoz needed just eight pitches (five strikes) to retire the top of the Rangers' lineup after the Mariners pulled ahead in the eighth inning. This was just his third appearance in September after he battled elbow soreness early in the month. Munoz is up to 21 saves in 26 chances to go with six holds, a 2.14 ERA, a 0.97 WHIP and a 71:25 K:BB through 54.2 innings this year.

Miller earned the save in Friday's 2-0 win over the White Sox, pitching a scoreless inning with two strikeouts while allowing one hit.

The Oakland closer worked around a one-out Andrew Vaughn single to pick up his 25th save of the season, good for sixth in the AL. Miller has not blown a save since returning from the injured list Aug. 7. Since that date, he has collected 10 saves while pitching to a 2.50 ERA, 0.88 WHIP and 23:5 K:BB across 18 innings.