NEW YORK -- Yankees ace Gerrit Cole threw off a mound Saturday morning for the first time since being shut down in mid-March, checking off another box in his road back from an elbow injury.

Cole took the mound in the Yankees' bullpen at 10:40 a.m., hours before New York took on the Detroit Tigers at Yankee Stadium. He said he threw 15 pitches, 13 for strikes and all fastballs. He said the pitches averaged 89 mph.

"It was exciting," Cole said. "This was a good day for me. I was fired up."

Cole, 33, started the season on the 60-day injured list after being diagnosed with nerve irritation and edema in his pitching elbow following one spring training outing. The reigning American League Cy Young Award winner is eligible to come off the injured list May 27, but the Yankees have declined to share a timetable for Cole's return.

On a scale from 1 to 10 -- 10 being game ready -- Cole reported he is "somewhere between 1 and 5." He said how his body responds over the next 48 hours will decide when he throws off a mound again.

Cole's injury was a significant blow to a club with championship-or-bust aspirations, but the Yankees' starting rotation has been one of the best in the majors and a primary reason for the team's 21-13 start. The rotation's 3.43 ERA through Friday ranked ninth in the majors. Its 183 innings pitched ranked fourth.

Luis Gil, Cole's rotation replacement, logged the best start of his young career Wednesday, holding the explosive Baltimore Orioles scoreless on two hits over a career-high 6 innings. Gil, 25, has recorded a 3.19 ERA in 31 innings across six starts despite leading the American League with 20 walks.

Earlier this week, Yankees manager Aaron Boone said neither the team's nor the rotation's success will impact Cole's timeline. Asked whether the overall success has made his absence more "palatable," Cole was unsure.

"I don't really have anything unpalatable to compare it to," Cole said. "You know what I'm saying? So I'm just kind of like, just like everybody else, just glad we're playing well."

Also on Saturday, the Yankees reinstated infielder Jon Berti from the 10-day injured list and designated former first-round pick Taylor Trammell for assignment.

Berti, 34, has been out of the Yankees' lineup since April 10 with a left groin strain. The Yankees had selected Trammell off waivers from the Los Angeles Dodgers on April 18, and he collected 1 hit, 1 walk and 2 runs in five games with New York.

Field Level Media contributed to this report.