The Oakland A's, barring a collapse in the last two weeks of the abbreviated season, are headed to the playoffs. The Colorado Rockies need to rally to get into the playoff bubble, and getting a win in the second of a two-game series with Oakland is vital.

The Rockies (22-25) squandered a fast start in July and early August and are trying to recover. They have their ace, German Marquez, going against A's right-hander Mike Fiers on Wednesday afternoon, as every game from here on out carries importance.

"We're in position even though we haven't played great over the last three weeks or so," Rockies manager Bud Black told reporters Tuesday of the playoffs. "I know the guys in the room want to make the playoffs, but we've got to get it done between the lines. Our mindset is to make the playoffs. We're in position."

Colorado's recent struggles have not helped. Even after Tuesday's 3-1 win over Oakland the Rockies have dropped nine of their last 14, and they have won consecutive games just once in the last two weeks.

Having Marquez (2-5, 4.35 ERA) going is a good thing, considering his short history against Oakland. He beat the A's on the road July 29, allowing one run on four hits and striking out eight in six innings and also beat them in 2018 at home.

He is 2-0 against the A's in those two starts, tossing 13 2/3 innings while giving up three runs and fanning 16.

Oakland (30-19) has stayed atop the American League West despite dealing with injuries, and it will have to play the rest of the season and playoffs without its All-Star third baseman Matt Chapman. Chapman had surgery Tuesday to repair a torn labrum in his left hip and is expected to face four months of recovery.

"Obviously, we have plenty of time prior to Spring Training," A's head trainer Nick Paparesta said on Tuesday. "Once we get him into Spring Training, we'll get him through our progression program for his running and then baseball activities and see where we are at that time."

Oakland signed infielder Jake Lamb off waivers on Monday and he doubled and scored a run in Tuesday's win. The A's also got some good news on the injury front when outfielder Stephen Piscotty was said to be day to day with a right knee that forced him out of the first game of Monday's doubleheader in Seattle.

Oakland hopes Fiers (5-2, 5.06) can have his first good outing against Colorado. In two career appearances against the Rockies he is 0-1 with a 24.00 ERA. He has started just one game against them, in 2012 when he was with Milwaukee, and was hit hard. He gave up eight runs on nine hits and lasted just two innings.

Fiers has pitched well lately, going 4-1 with a 3.81 ERA and two home runs allowed over his last five starts after going 1-1 with a 6.86 ERA and six home runs over his first four starts. The A's are 7-2 in his nine starts this season.