Alonso likely to make Mariners debut in Oakland

Yonder Alonso might struggle with the little things. Like where to park at the Oakland Coliseum. Which clubhouse door to take. When batting practice starts.

The Seattle Mariners hope the All-Star first baseman has no problem with the bigger things, like driving in runs.

The Mariners acquired Alonso in a trade with the Oakland Athletics on Sunday in exchange for minor league outfielder Boog Powell.

Alonso is expected to make his Mariners debut Tuesday when the teams open a two-game series in Oakland.

Alonso admitted Sunday he was stunned when told of the trade.

"Surprised but excited, going to a team that is one game out of the playoffs," Alonso said. "I get to play some meaningful baseball, which will be probably the first time in my career I'll be able to do that. I'm ecstatic."

In eight seasons with Cincinnati (2010-11), San Diego (2012-15) and Oakland (2016-17), Alonso has hit .269 with 61 home runs and 288 RBI in 762 games.

The 30-year-old made his first All-Star Game this season, batting .266 with a career-high 22 homers and 49 RBI in 100 games with the A's.

"Yonder fits our roster quite well," Mariners general manager Jerry Dipoto said after the trade was announced. "Obviously, he's had an excellent year to this point, an All-Star season, real breakout year for him. We are acquiring a bat that gives us a difference in the middle of our lineup.

The left-handed-hitting Alonso is likely to platoon with his former Oakland teammate Danny Valencia at first base. The two were friends when with the A's, and Valencia was one of the first players Alonso texted after learning of the deal.

"I feel like it's a complement he brings to our lineup, particularly the left-handed bat and how he pairs with Valencia, which they've done before," Dipoto said. "It's a balance he brings to our lineup, especially looking ahead, we've got quite a stretch of right-handed starters that we are seeing over the next three weeks. This is something we discussed for a length of time heading into the July 31 deadline. We felt like we were at the goal line to get a deal done. And through the August trade period, we were able to complete it."

Powell, originally drafted by Oakland in the 20th round in 2012, batted .194 in 23 games with the Mariners this season. He was hitting .340 at Triple-A Tacoma.

"Clearly they're going young, and they're going to be patient as well," Alonso said of the A's. "I think definitely the sky is the limit here with these young guys. There is a lot of talent in this clubhouse. ... The future is bright here."

The A's plan to call up Matt Olson and platoon him at first base with Ryon Healy.

"It's time for Matt Olson to get a chance to play here," A's manager Bob Melvin said Sunday. "A few years ago, this guy was our top prospect, and he does a lot of things really well. He's a great defender. He's having a good season, he gets on base. This kind of opens the door for him and Healy to match up at first base, and stays along with the theme that we're getting younger."

Olson, 23, is batting .272 with 23 homers and 60 RBI in 79 games at Triple-A Nashville. In five previous stints with the A's this season, he hit .196 with four homers and nine RBI.

"Obviously, I can't thank the Oakland A's enough for the opportunity they gave me," Alonso said. "They believed in me and helped me mature and recharge my career."

Alonso likely will make his Mariners debut in the series opener as Oakland is scheduled to start right-hander Kendall Graveman (2-3, 4.96 ERA). Graveman is 1/3 with a 4.82 ERA in eight career appearances against Seattle, including six starts. He has not faced the Mariners this season.

The Mariners are set to counter with left-hander Ariel Miranda (7-5, 4.41 ERA), who is 0-1 with a 5.40 ERA in two career starts against the A's. He took the loss April 22 at Oakland, giving up four runs on seven hits in three innings during Seattle's 4-3 defeat.