SEATTLE -- The Mariners had an off-day on Monday to travel across the country for the start of an eight-game road trip in Washington, D.C., on Tuesday, but that didn't slow general manager Jerry Dipoto from continuing his flurry of roster moves as the club attempts to deal with a rash of injuries.
The club is also expected to activate second baseman Robinson Cano from the 10-day disabled list prior to Tuesday's 4:05 p.m. PT game against the Nationals, but that move has not been announced yet, as Cano isn't eligible to come off the DL until Tuesday.
Since setting their Opening Day roster 50 days ago, the Mariners have made 79 transactions involving their 40-man roster. While getting off to a 20-25 start, Seattle has used 42 players on its 25-man roster in the first 45 games of the year, most in the Majors. That includes an MLB-high 11 different starting pitchers.
Zunino will return as the starter behind the plate after getting a 12-game breather in Tacoma to work on his hitting approach. The 26-year-old catcher hit .293 with two doubles, five home runs and 11 RBIs in 12 games for Tacoma and homered three times in his final two games.
Zunino struggled in the first month-plus of the season with Seattle, posting a .167/.250/.236 line with no home runs and two RBIs in 24 games, but he's strong defensively and Gosewisch batted just .071 with no extra-base hits in 28 at-bats over 11 games after being called up to replace Zunino on May 5.
Seattle's backup catcher, 38-year-old Carlos Ruiz, is batting just .133/.259/.200 in 45 at-bats.
Pagan, a right-hander, adds another bullpen arm for now, but the Mariners will need to name a starter to take Heston's spot before that turn comes up on Saturday in Boston. Heston gave up seven runs (six earned) on seven hits in three-plus innings during his first start of the season in Sunday's 8-1 loss to the White Sox.
Due to their short-handed rotation, the Mariners are going with nine relievers for now with the addition of Pagan. The 26-year-old rookie pitched in two games earlier this month for Seattle, allowing four hits and five runs in 2 2/3 innings. He is 1-0 with a 3.24 ERA and two saves in 10 appearances for Tacoma.
Vogelbach was called up on Sunday and started at first base while Danny Valencia deals with a sore right wrist. But an MRI exam showed no fracture for Valencia, who's expected to be available by Tuesday or Wednesday.
With Cano returning, utility infielder Taylor Motter can play first base if needed as well until Valencia is ready.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB. This story was not subject to the approval of Major League Baseball or its clubs.