Former Vanderbilt star Kumar Rocker underwent shoulder surgery in September, receiving what his agent called "a minor scope" on his right arm, sources familiar with the procedure told ESPN.

Rocker, the 10th overall pick in the 2021 draft, did not sign with the New York Mets after the team balked at the condition of his pitching arm. Now 22 and again draft-eligible, Rocker has steadily climbed teams' boards over the past month after regularly hitting 98 mph with his fastball in a dominant five-game stint with the Tri-City ValleyCats of the independent Frontier League.

"We have a very clear understanding, after a minor scope, of Kumar's medically documented health, which has allowed him to perform at the highest levels," said Scott Boras, Rocker's agent.

Rocker's medical information, including the procedure performed by Dr. Neal ElAttrache, was distributed to teams in recent days leading up to the July 17 draft, in which he is expected to again go in the first round. In a draft short on pitching, Rocker's combination of pedigree and the stuff he showed with Tri-City could compel teams to consider him far earlier than they were in recent months.

Following a breakout performance as a freshman in which he was named Most Outstanding Player during Vanderbilt's run to a College World Series title, Rocker spent the next two years as the most recognizable name in college baseball. His final season with Vanderbilt in 2021 was characteristically excellent, with 179 strikeouts in 122 innings and a 2.73 ERA, but his fluctuating velocity concerned teams at the top of the first round.

The Mets were initially elated he dropped to them and planned to offer a $6 million signing bonus -- $1.26 million more than the slot value of the 10th pick. Concerned by his medicals, New York never made an offer. The Mets received the 11th pick in this year's draft as compensation. Typically, teams need to offer 40% of slot value to collect the comp pick, but the Mets were exempted from doing so because Rocker did not participate in Major League Baseball's pre-draft MRI program.

The procedure was not considered major and did not involve Rocker's rotator cuff or labrum, Boras said. Rocker returned to the mound early in the year to build up to his June 5 debut with Tri-City, which is 23-20 this season. In his five outings, he threw 20 innings, struck out 32, walked four and posted a 1.35 ERA. Rocker's final performance on Friday was his best: five innings, two hits, no earned runs, one walk, seven strikeouts and 44 strikes on 69 pitches against the Empire State Greys, who are 2-40.