Kurtz (oblique) isn't in the lineup for Saturday's game against Texas.

Oblique soreness forced Kurtz to make an early exit from Friday's game, and the issue is apparently severe enough to keep him from playing Saturday as well. While the 22-year-old rookie takes a day to recover, Tyler Soderstrom will shift to first base with Carlos Cortes patrolling left field.

The Red Sox optioned Sogard to Triple-A Worcester on Saturday.

Sogard was called up from Worcester on Friday and went 0-for-3 with a walk and a steal while starting at second base in a loss to Pittsburgh. However, he'll end up spending just one day with Boston before heading back down. Sogard's demotion made room on the 26-man roster for Nathaniel Lowe to be reinstated off the paternity list.

The Red Sox reinstated Lowe from the paternity list Saturday.

Lowe is back with Boston after taking two days off while on paternity leave. However, he's not starting Saturday, as Romy Gonzalez is manning first base against Pittsburgh. To make room for Lowe on the active roster, the Red Sox optioned Nick Sogard to Triple-A Worcester.

Gonzalez started at first base and went 3-for-4 in Friday's 4-2 loss to Pittsburgh.

Gonzalez started a second consecutive game at first base, as Nathaniel Lowe remains unavailable while on paternity leave. Gonzalez had a go-ahead, run-scoring single Thursday in Baltimore to achieve a sweep of the Orioles and then followed up with three singles off the Pirates' Paul Skenes, one of the best pitchers in the game.

Duran started at shortstop and went 0-for-4 in Friday's 5-2 win over the Athletics.

Duran got the start at short in the first game after Corey Seager underwent appendectomy surgery Thursday. Duran eventually moved to second base in the seventh inning, when Josh Smith moved from first base to short. Duran (against lefties) and Smith (righties) should share the position while Seager is on the mend.

Mountcastle went 3-for-5 with two doubles, four RBI and one run scored in Friday's 15-8 loss to the Giants.

Mountcastle had Robbie Ray's number, delivering all three hits over the first five innings of the game. Since returning from a Grade 2 hamstring injury, Mountcastle has gone 21-for-73 (.288) with five extra-base hits and 12 RBI over 19 contests. The first baseman has reclaimed a starting role in the lineup and is up to a .258/.294/.365 slash line with four homers, 16 doubles, 27 RBI, 26 runs scored and three stolen bases over 71 games this season.

Mayo went 1-for-4 with a solo home run in Friday's 15-8 loss to the Giants.

Since his homer Aug. 15 versus the Astros, Mayo had gone just 4-for-39 (.103) with a 3:16 BB:K over 10 contests. The infielder was able to snap his power drought Friday, but he hasn't posted a multi-hit effort since Aug. 6 versus the Phillies. Mayo is up to six homers, 20 RBI, 20 runs scored, one stolen base and a .189/.268/.335 slash line over 60 contests this season. While his playing time has been steady this month, the lack of reliable production makes the 23-year-old tough to roster in redraft formats.

Kurtz was removed from Friday's game against the Rangers with right oblique soreness, Martin Gallegos of MLB.com reports.

After scoring from second base during the third inning, Kurtz was replaced in the field to begin the fourth frame. The severity of his injury remains unknown, though the A's may play it safe and hold the rookie slugger out for a game or two. If that ends up being the case, Tyler Soderstrom and Brett Harris would be in play to start at first base.

The White Sox recalled Elko from Triple-A Charlotte on Friday.

The 26-year-old was sent to Charlotte in early August after recovering from a knee sprain but will receive another look in the majors with Miguel Vargas (hand) landing on the IL. Elko has a .145/.209/.355 slash line with four homers in his first 20 MLB games this season.

The Red Sox recalled Sogard from Triple-A Worcester on Friday, Chris Cotillo of MassLive.com reports.

Sogard will be part of the 26-man roster for the first time since being optioned June 30. He replaces Jhostynxon Garcia. Sogard has slashed .254/.323/.339 in 65 plate appearances with the Red Sox this season.