Rivas will start at second base and bat ninth in Sunday's game against the Cardinals.

Since being called up from Triple-A Tacoma when the Mariners' active roster expanded from 26 to 28 men, Rivas has gone 3-for-10 with a pair of extra-base hits and two walks. Though the sample has been small, Rivas' performance appears to have at least temporarily allowed him to overtake Cole Young as Seattle's preferred option at the keystone. The switch-hitting Rivas will be included in the starting nine for the third time in four games, including a second straight matchup versus a right-handed starting pitcher (Miles Mikolas).

Mariners manager Justin Hollander said Monday that Bliss (biceps) tore the meniscus in his right knee while on a rehab assignment with Triple-A Tacoma and is out for the rest of the season, Tim Booth of The Seattle Times reports.

Bliss had been on the shelf since April 9 due to a left biceps tear that required surgery, but he appeared to be on the cusp of a return from the 60-day injured list after going 5-for-13 with three doubles, four walks, two stolen bases and seven RBI through his first six rehab games with Tacoma. Unfortunately for the 25-year-old infielder, he seemingly suffered the knee injury over the weekend and required another surgery Monday. Hollander didn't provide a timeline for Bliss' return from the knee procedure, but if Bliss required a full repair of the meniscus, he could be out of action for the start of spring training.

Young is absent from the lineup for Monday's game against the Cardinals.

The left-handed-hitting Young has now been out of the lineup for five consecutive games, and Monday marks the third time during that stretch that he's sat against a right-handed starting pitcher (Miles Mikolas). Leo Rivas will get the nod at the keystone in the series opener with St. Louis and may have overtaken Young as the Mariners' preferred option at the position. Young's drop in playing time comes while he's gone just 2-for-38 (.053 average) over his last 15 games.

Hamilton went 1-for-3 with one RBI, one stolen base and one run scored in Sunday's 7-4 win over the Diamondbacks.

Hamilton's playing time has dropped significantly over the last week -- this was his first start since Aug. 30. Romy Gonzalez and Nick Sogard have combined to handle second base, leaving Hamilton as a bench bat and defensive replacement in most games. He's still logged two steals over five games in September and is up to 20 thefts on 25 attempts this season. The infielder has added a .203/.259/.316 slash line, four home runs, 16 RBI, 25 runs scored, four doubles and one triple over 173 plate appearances.

Keaschall went 1-for-4 with two stolen bases and a run scored in Sunday's 5-1 victory at Kansas City.

The Minnesota rookie was credited with a swiping home on double-steal attempt in the sixth to give his team a 4-0 lead. Since returning from a forearm injury Aug. 5, Keaschall has produced like a star for the Twins, batting .313 (36-for-115) with four homers, six steals, 20 RBI and 15 runs scored across 29 contests. Overall, the 23-year-old is now slashing .321/.405/.485 with 11 stolen bases, 22 RBI and 19 runs scored in 153 total plate appearances.

Sosa went 2-for-4 with a homer, a walk, three RBI and an additional run scored in Sunday's 6-4 victory over the Tigers.

The 25-year-old Venezuelan walloped a titanic 451-foot solo shot off Detroit starter Charlie Morton in the third to tie the contest at 3-3. Sosa has been a great source of power since the All-Star break, launching 11 long balls while batting .256 (44-for-172) with 34 RBI and 23 runs scored in 44 games. Across 485 total plate appearances, the Chicago infielder is now slashing .263/.295/.435 with 65 RBI and 50 runs scored.

Rengifo is out of the lineup for Sunday's game against the Athletics.

Rengifo will get the afternoon off Sunday after he started in each of the Angels' last eight contests. Chris Taylor will fill in for Rengifo at second base and will bat fifth.

Urias is out of the lineup for Sunday's game against the Rangers.

Urias started five straight games from Aug. 31 to Sept. 4, but he finds himself on the bench Sunday for the third straight game while in the midst of a 5-for-28 (.179) slump. Mauricio Dubon is receiving the start at second base in the series finale for Houston.

Frazier is out of the lineup for Sunday's game against the Twins.

After starting the last five games and going 3-for-16 with one home run, one double, two walks, three runs and two RBI, Frazier will receive a breather. The Royals will go with Michael Massey at second base and Randal Grichuk in left field in the series finale.

Gimenez is out of the lineup for Sunday's game against the Yankees, Shi Davidi of Sportsnet.ca reports.

Gimenez started the previous 20 games and will receive a day off after posting a .185/.243/.292 slash line during that stretch. Davis Schneider is manning the keystone in Sunday's series finale for Toronto.