One team playing its best baseball of the season meets another that hopes it is trending in that direction when the Oakland Athletics host the Miami Marlins in the opener of a three-game interleague series Friday night.

The A's have won four in a row -- their longest winning streak since last June -- after taking three straight from the Pittsburgh Pirates to open a 10-game homestand.

Oakland's upturn has been fueled by two unusual sources -- backup infielders and relief pitchers.

Tyler Nevin, subbing for injured J.D. Davis, went 6-for-10 with two home runs, four RBIs and three runs in the Pittsburgh series. Abraham Toro, who was replacing injured Zack Gelof, went 5-for-8 with a homer, two doubles, two RBIs and three runs.

The A's scored only 14 runs in the sweep, but that was 14 more than the Pirates totaled against the Oakland bullpen. Oakland's relievers threw four shutout innings in Monday's 5-1 win, five in Tuesday's 5-2 triumph and three in Wednesday's 4-0 victory.

Closer Mason Miller was the star of the relief corps, striking out four of the six batters he faced in the ninth inning on Tuesday and Wednesday, needing just 26 pitches to wrap things up.

Miller, a converted starter who has thrown more 100 mph pitches than anyone in the majors this season, admitted he gets a special pleasure when triple digits flash on the stadium scoreboard.

"Yeah, I sneak a couple looks for sure," he said. "Usually it doesn't end up being my best one. When I come in (to the clubhouse), somebody will let me know. Or somebody will text me, and obviously we have video after the game. I think everybody that says they don't (check the radar gun) is lying a little bit. Everybody likes to take a little look."

Like most teams, the Marlins have never seen Miller, who made his major-league debut last April and has appeared in just 22 games. Miami also never has faced Oakland's projected starter in the series opener, left-hander JP Sears (1-2, 4.64 ERA).

Sears, 28, was the starting pitcher the last time the A's lost, a 7-0 decision last Saturday in Baltimore. He was roughed up for seven runs in 6 1/3 innings, after having held the Texas Rangers, St. Louis Cardinals and New York Yankees to a total of one run over 17 1/3 innings in his previous three outings.

The Marlins flew across the country Thursday night to begin a six-game California swing riding the momentum of a three-game sweep of their own against the Colorado Rockies. Miami, which began the series just 6-24, capped the trifecta with a 5-4 triumph in 10 innings on get-away day.

"We're very confident," Jesus Sanchez said moments after his walk-off single. "Miami is back."

As is the case with Friday's counterpart, Marlins left-hander Ryan Weathers (2-2, 4.55) has never faced the A's. And like Sears, the 24-year-old is coming off his worst outing of the season, a 12-9 home loss to the Washington Nationals in which he gave up six of the runs in four innings.

--Field Level Media