David Rollins, LHP, optioned to AAA Tacoma (post-game 7/4).
Adrian Sampson, transferred to the 60-day disabled list (right flexor bundle strain).
Robertson (#99) will be in uniform and available for tonight's game (5:10 pm PT) at the Houston Astros.
Robertson, 30, was batting .262 (65x248) with 26 runs, 8 doubles, 6 triples, 4 home runs, 25 RBI, 21 walks and 7 stolen bases in 73 games with AAA Tacoma this season. Robertson currently ranks T2nd in the Pacific Coast League with 6 triples. Robertson has hit safely in 45 of 73 games this season, including 17 multi-hit contests. In 73 games with Tacoma, Robertson appeared at left field (32 G, 25 GS), 2nd base (20 G, 19 GS), center field (13 G, 11 GS) and right field (13 G, 12 GS).
Robertson was claimed off waivers from Los Angeles-AL by Seattle on Nov. 6, 2015. In parts of 2 Major League seasons with Texas (2014) and Los Angeles-AL (2015), Robertson is a career .274 (69x252) hitter with 33 runs, 11 doubles, 1 triple and 28 RBI in 107 career games. Robertson attended Oregon State University for his senior season after playing three years at Concordia University (Irvine, CA).
Rollins, 26, has struck out 4 and walked 3 in 4 scoreless outings, all in relief, over two stints with the Mariners this season. Since being recalled from AAA Tacoma on June 24, Rollins was 0-0 with a 0.00 ERA (0 ER, 2.2 IP) with 4 strikeouts and 3 walks in 3 relief appearances. Rollins appeared in one game with Seattle earlier this season, tossing 1.1 scoreless innings on June 17 at Boston, before being optioned to AAA Tacoma on June 18.
Rollins is 2-0 with a 2.05 ERA (7 ER, 30.2 IP) with 26 strikeouts and 1 walk in 24 games with Tacoma this season, all in relief. Overall, he has allowed earned runs in just 5 of his 24 appearances with Tacoma, and has allowed more than 1 run just once. Rollins was selected by Seattle from Houston in the Rule 5 Draft on Dec. 11, 2014. In parts of 2 Major League seasons with Seattle, Rollins is 0-2 with a 6.52 ERA (21 ER, 29.0 IP) with 25 strikeouts and 11 walks in 24 career games.
Sampson, 24, was 0-1 with a 7.71 ERA (4 ER, 4.2 IP) in 1 start with the Mariners, before being placed on the 15-day disabled list on June 24. Sampson is eligible to be activated from the 60-day disabled list on August 23. Sampson was scheduled to be the starting pitcher on June 23 at Detroit, but was replaced after feeling discomfort in his right elbow while warming up for the first inning. Sampson made his Major League debut on June 18 at Boston, allowing 4 runs on 8 hits while striking out 2 and walking 1 over 4.2 innings pitched. With his debut, Sampson, a native of Redmond, WA, became the 6th pitcher born in the state of Washington to make at least 1 start for Seattle. Prior to being selected, Sampson was 7-4 with a 3.25 ERA (29 ER, 80.1 IP) with 61 strikeouts and 12 walks in 13 starts with AAA Tacoma this season.