DENVER — Coby Mayo is headed back to the majors.

The Orioles’ infield prospect, ranked the No. 1 player in their farm system by MLB Pipeline, is expected to join the team in Colorado on Sunday when their active roster expands, a source with direct knowledge of the decision told The Baltimore Sun. It will be Mayo’s second stint with Baltimore.

Mayo, 22, took over the No. 1 spot on MLB Pipeline’s rankings on Friday when Jackson Holliday exceeded his prospect eligibility. The 2020 fourth-round draft pick went 1-for-17 at the plate during his first stint with the club in early August but has been one of the most productive power hitters in the minor leagues this season with 22 home runs at Triple-A Norfolk.

“There’s still a lot of season left,” executive vice president and general manager Mike Elias said when Mayo was sent down Aug. 15. “We also have roster expansion coming up in September and this is something that maybe won’t last very long. Maybe it will, but the possibility of him coming back up is always going to be front and center. I thought it was good for him. He got a taste of the big leagues after putting in a really good stint in Triple-A.”

Since returning to Norfolk, Mayo has hit .222 with two home runs and a .782 OPS in 10 games. He’s played seven of those games at third base and three at first, the latter of which could be a position he plays in the majors for the first time with Ryan Mountcastle on the injured list with a wrist injury. Incumbent third baseman Ramón Urías has also been one of the Orioles’ most productive hitters of late, slashing .268/.338/.535 in August.

On the year, the Parkland, Florida, native has a .981 OPS in Norfolk. He made a strong push for a roster spot in spring training but was one of several prospects who couldn’t crack the Orioles’ deep group. With All-Star third baseman Jordan Westburg still weeks away from a potential return from a broken hand, Mayo will have several paths to playing time as Baltimore makes a run at winning back-to-back American League East titles.

MLB allows teams to expand its active rosters from 26 to 28 players beginning Sept. 1. With Mayo slated to fill one of the spots, the Orioles are hopeful right-hander Zach Eflin can fill the other. Manager Brandon Hyde said Friday that the veteran starter is “probable” to return from the 15-day injured list with right shoulder inflammation and start against the Colorado Rockies for their series finale.