Frazier (thumb) has returned from his rehab assignment and was reinstated from the 10-day injured list Friday.

Frazier required only one rehab game with Double-A Northwest Arkansas, where he went 0-for-4 with a strikeout, before being cleared to return. Frazier is slashing .211/.297/.299 across 165 plate appearances with the Royals and should mix in at third base and in right field.

Massey went 1-for-4 with a solo home run and an additional run scored in Thursday's 10-8 loss to the Rays.

Massey started at second base for the first time since he returned from the injured list June 24. Prior to Thursday's game, Joel Goldberg of Bally Sports Kansas City reported that the Royals' plan is to get Massey some playing time in the field before the All-Star break. He had previously been limited to designated hitter as the team eases him back in following another back injury. With Massey approaching full health, Maikel Garcia may shift back to third base more frequently, while Nick Loftin and CJ Alexander are in line for reduced roles. Massey is slashing .273/.289/.516 with eight homers, 25 RBI, 21 runs scored and no stolen bases over 137 plate appearances this season.

Horwitz went 3-for-4 with two RBI in Thursday's loss to the Astros.

Batting fifth as a late addition to the lineup when Bo Bichette (forearm) was scratched, Horwitz banged out all three of his singles against same-handed pitchers, getting knocks off southpaw Framber Valdez in the first and fourth innings before leading off the ninth with a hit off Josh Hader. Horwitz has been impressive at the plate since his promotion, slashing .314/.435/.486 through 85 plate appearances with three doubles, three homers, nine RBI and 11 runs.

Lowe went 3-for-5 in Thursday's win over the Royals with a double, a homer and three runs scored while also drawing a walk.

Lowe doubled in his second trip to the plate before coming around to score four batters later on a Jonny DeLuca single, extending Tampa Bay's lead to four runs. The second baseman then added a solo homer in the sixth and went on to reach four times in the contest - the first time he's done so this season. Lowe's three hits on the night also marked a season high, and he's now homered three of his last four games. Over that stretch he's batting .333 (5-for-15) with three RBI and six runs scored.

Keith went 2-for-4 with a solo home run in Thursday's 12-3 loss to the Twins, which was called after seven innings due to rain.

Keith was a bright spot for the Tigers on an ugly afternoon in Minneapolis. The young second baseman now has consecutive multi-hit efforts, and he's tripled and gone deep during the stretch. Overall, Keith has been so-so this year with a .236 average and .620 OPS, though he's been better from May onward after a rough first month in the majors. There's still potential for a big finish from the 22-year-old rookie.

Gelof went 0-for-3 with a walk, a stolen base and a run scored in Thursday's 5-0 win over the Angels.

The steal was Gelof's 10th of the year. He's picked up two of those thefts during an eight-game stretch in which he's gone 7-for-27 with a 4:13 BB:K. The second baseman is at a .201/.263/.361 slash line with nine home runs, 23 RBI and 30 runs scored over 67 contests, and his 36.2 percent strikeout rate is weighing down the rest of his stat line.

Frazier (thumb) began a rehab assignment with Double-A Northwest Arkansas on Thursday.

Frazier has been on the injured list since June 24 due to a strained right thumb, but he's now been given the green light to test his thumb in a competitive environment. It's unclear how long the 32-year-old will remain in the minors, but a return before the All-Star break remains a possibility.

Polanco is not in the lineup for Thursday's game against the Orioles.

Polanco was given a semi-day off Wednesday in the designated hitter slot and will be out of the lineup altogether Thursday. Ryan Bliss is getting the start at second base for the Mariners.

Horwitz is out of the lineup for Thursday's game against the Astros.

Hortwitz will head to the bench Thursday with lefty Framber Valdez on the mound for Houston. Leo Jimenez will man second base and bat eighth in the series finale.

Semien is absent from the lineup for Thursday's game against the Padres.

It's just the second day off of the season for Semien, who has managed just two hits over his last 36 at-bats. Jonathan Ornelas will handle second base for the Rangers on Thursday while Semien receives some much-needed rest.