SEATTLE — The Seattle Mariners got through the Monday MLB trade deadline with two new acquisitions to the team, who both arrived to the Pacific Northwest ahead of the first of a three-game series against the Detroit Tigers on Tuesday at T-Mobile Park.

The Mariners acquired right-handed reliever Seranthony Dominguez from the Chicago White Sox in return for veteran starting pitcher Luis Castillo on Saturday.

On the day of the deadline Monday, Seattle added to its outfield with the addition of Taylor Ward from the Baltimore Orioles.

Both players will likely play a huge factor in the Mariners' final push for a second-straight playoff appearance. The Mariners entered Saturday 2.5 games behind the Houston Astros for first place in the American League West and 2.5 games out of the final AL wild card spot.

Dominguez, who was experience as a closer, will be used in a variety of roles ranging from middle-to-high leverage, which will give Seattle more established arms a breather before the impending returns of Carlos Vargas and Matt Brash, both of whom are likely to return this month from respective lat strains.

"Another great addition," Mariners manager Dan Wilson said in a pregame interview Tuesday. "I think (president of baseball operations Jerry Dipoto) and (general manager Justin Hollander) did a really nice job of getting some pieces we really needed and finding that bullpen arm that has versatility there, too. (Dominguez) has seen a lot of different roles throughout his career. He's experienced. I think he'll fit right in with guys we have down there."

Dominguez has some familiarity with his new bullpen-mates and trains with Vargas in the offseason.

"I want to be a good teammate, a good friend," Dominguez said in a pregame interview Tuesday. "Just do my best. ... I hear a lot of good things about (the Mariners) and I saw it last year, too, we played them in the American League championship (when I was with the Toronto Blue Jays) and they're really good. They play really hard."

Ward, who has dominant splits against left-handed pitchers (.269/.413/.426 slash line; 141 wRC+), is expected to be an everyday starter in the outfield and designated hitter spot,  which will due to the team well given the potential season-ending injury to outfielder Luke Raley.

The 32-year-old also has familiarity playing at T-Mobile Park due to his eight-year tenure with Seattle's American League West rivals, the Los Angeles Angels.

"The fanbase here, they love the team and they support them," Ward said Tuesday. "It's always tough coming here as a visitor. To be here, on their side, looking forward to it. ... I'm just happy not to face the (M's) pitching staff anymore."

The two players' arrival to Seattle also coincides with utility player Brendan Donovan being activated off the injured list after missing two-and-a-half months with a left groin strain.

Ward will bat eighth in the lineup Tuesday as the DH whereas Donovan will play third base and bat seventh.

"I think some of (the lineup) will depend on health and whatnot," Wilson said. "I see Taylor getting a lot of time out in right field. (Dominic Canzone) has done a really nice job out there, he's also done a really nice job DH'ing, which can be difficult. I think he handles that role very well. (Donovan) will fill in when guys need a day, whether it's a DH day or a day off completely. We'll kind of watch it as we go."

-- The Mariners several additional roster moves ahead of their series against the Tigers. They released backup catcher Mitch Garver and recalled catcher Jhonny Pereda from the Triple-A Tacoma Rainiers, released outfielder/designated hitter Rob Refsnyder and designated outfielder Stuart Fairchild for assignment.