Updated

SEATTLE -- The Baltimore Orioles come sweeping into Safeco Field with a seven-game winning streak and a powerful sense of momentum.

The Orioles (47-30) have already hit 55 home runs this month, matching the major league record for June. Mark Trumbo matched the record when he hit his league-leading 23rd homer of the season in Wednesday's 12-6 win over San Diego. That victory opened up a 5 1/2-game lead over Boston atop the American League East standings.

No team in the AL has as much power as the Orioles, but the Seattle Mariners, who host Baltimore on Thursday, are one of the few teams that are close. Seattle's 113 home runs this season rank third in the AL, 11 behind the league-leading Orioles.

The primary home-run hitter for each team is familiar to the other. Baltimore's Trumbo finished last season with the Mariners before being dealt for backup catcher Steve Clevenger in an offseason deal designed to get rid of Trumbo's salary.

Leading the Mariners with 20 home runs is former Oriole Nelson Cruz, who signed a free-agent deal with Seattle before the 2015 season and has been everything the Mariners could have hoped he'd be. Cruz matched his 2014 total of 40 home runs in his first season with the Mariners and is on pace to get there again this season.

Unlike last season, when the Mariners fell out of the playoff race early with a horrific start to a year that began with promise, this campaign has seen the offense come alive as Seattle started strong before injuries to the starting rotation derailed things. Cruz is one of six different Seattle players who have already hit 10 homers, and yet the Mariners (39-39) are more than just a power-hitting team.

"We have a good team," Cruz said after hitting his 20th home run of the season Tuesday night. "We can do a lot of things, not just the long ball."

The Orioles are also much more than just a home-run hitting team, but it's hard to ignore the numbers they've been putting up in that category. Trumbo leads four players who have hit at least 16 home runs, and it's not out of the question that all four will have 20 bombs by the All-Star break.

It all adds up to a league-best 124 home runs, with 55 of them coming in June. The Orioles will close out the month with a shot at breaking the June record on Thursday.

"Obviously, it's a special thing, but it's not something that anyone is going to gloat about or spend too much time thinking about," Trumbo told MLB.com after Wednesday's win over Detroit. "It just goes to show that we are on a nice little run."

The Orioles will start right-hander Chris Tillman, who is 10-1 this season and has dominated the franchise that included him in a big trade for Erik Bedard a few years ago. Tillman is 7-0 with a 2.96 ERA in his career against the Mariners.

Seattle will start right-hander Taijuan Walker, a former top prospect who has battled nagging injuries this season. Walker skipped his last start due to a sore foot and was limited to five innings the last time he was able to pitch.