SEATTLE -- Looking to bolster their roster for the final month, the Mariners brought up five players from Triple-A Tacoma before Friday's 3-2 win over the A's and activated center fielder Jarrod Dyson from the 10-day disabled list as Major League rosters were allowed to expand for September.
The club also placed reliever David Phelps on the 10-day disabled list with an impingement in his right elbow after he was removed from Wednesday's game in Baltimore. Phelps is going on the DL for the second time since being acquired from the Marlins on July 20. He's 2-1 with a 3.12 ERA in 10 appearances.
Catcher Mike Marjama and pitchers Dan Altavilla, Andrew Moore, Shae Simmons and Ryan Garton were all added from Triple-A. The club also activated right-hander Mike Leake, who was acquired from the Cardinals in a Wednesday trade. He started Friday night's game against the A's.
"Obviously the bullpen arms are a welcome addition," manager Scott Servais said. "With the toll we put on our bullpen, going to those guys so early in games because our starters haven't been able to go deep, these guys are all going to get a chance to pitch in meaningful spots in games."
Marjama and Simmons had to be added to the 40-man roster, but the Mariners opened spots there by outrighting the contract of right-hander Christian Bergman to Tacoma after he was put through waivers and lost right-hander Sam Gaviglio, who was claimed by the Royals after also being put through waivers.
That puts the Mariners' 40-man roster at 40, with 32 players now on the Major League roster and a few more likely to be added after Tacoma's season ends Monday.
Besides Leake, the only newcomers on the list are Marjama and Garton, who were both acquired from the Rays in a trade on Aug. 6, along with Simmons, who has been rehabbing an elbow issue much of the year. Leake will be the 38th pitcher used by Seattle this year and once Garton and Simmons get in games, the Mariners will tie the MLB record of 40 pitchers in a season, set by the 2014 Rangers.
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Marjama, 28, gives the Mariners a third catcher behind Mike Zunino and Carlos Ruiz. He hit only .169 with three home runs and 12 RBIs in 21 games for Tacoma, but batted .274 with nine homers and 51 RBIs in 72 games for Triple-A Durham in the Rays' organization prior to the trade. He has never appeared in a Major League game.
"It's a tremendous honor and privilege to be here and something I've waited for a long time," said Marjama. "It's been a long road and something that hasn't been easy. But for me, this day isn't about myself, it's more for the people who have supported me and been around me for seven years in professional baseball."
Garton is a 27-year-old who went 2-2 with four saves and a 2.80 ERA in 45 innings of relief between Durham and Tacoma this year, including 0-2 with a 6.00 ERA in seven outings with the Rainiers. He pitched in 44 games with the Rays over the last two seasons, going 1-3 with a 5.26 ERA and one save.

Altavilla rejoins the Mariners after being optioned back to Tacoma last Monday. He would have had to wait another five days to be recalled, but can be added prior to the 10-day period because he's replacing a player going on the DL in Phelps. The 24-year-old right-hander is 1-1 with a 5.19 ERA in 31 appearances over four different stints with Seattle this season.
Moore, who is rated as Seattle's No. 4 prospect by MLBPipeline.com, is another right-hander returning for his fourth stint with the Mariners this year. The 23-year-old rookie is 1-3 with a 6.34 ERA in seven outings, including six starts, and is expected to work out of the bullpen for now.
Simmons should also bolster the bullpen as he's finally healthy after a season-long battle with elbow issues. Since joining Tacoma on Aug. 4, he has posted a 3.68 ERA with six strikeouts and six walks in 7 1/3 innings over nine outings. The 26-year-old was acquired from Atlanta last winter and was expected to be a major part of Seattle's bullpen plans until being shut down during Spring Training.

Dyson has been on the 10-day DL since Aug. 17 with a strained groin and steps immediately back into the starting job in center field. He's hit .255 with 56 runs, 28 stolen bases and is fifth in the American League in defensive runs saved in the outfield with 15.
Dyson started in center field and went 0-for-3 on Friday.
Gaviglio's departure came as a bit of a surprise as the 27-year-old out of Oregon State started 11 games for Seattle earlier in the year and was 3-5 with a 4.62 ERA in 12 games overall. He'd gone 3-6 with a 3.97 ERA in 12 starts with Tacoma.
Bergman cleared waivers, and the 29-year-old remains in the organization, having gone 4-5 with a 5.00 ERA in 13 games, including eight starts earlier in the season.