CHICAGO -- Outfielder Brennen Davis, the MVP of the SiriusXM All-Star Futures Game last year and the Cubs' No. 1 prospect, underwent back surgery on Thursday in Los Angeles, sources told MLB.com.

One month after being shelved due to what was initially described as lower-back tightness, Davis underwent a procedure after persistent discomfort and that led to the discovery of a vascular malformation (a nest of blood vessels) that pushed against a nerve. The positive news was that no structural damage was found in Davis' back and the highly-touted outfielder is expected to make a full recovery. At this early stage, Davis' timeline for return is to be determined, making it unclear whether a comeback this season is realistic.

Davis, 22, is ranked as the Cubs' top prospect per MLB Pipeline and other outlets and entered this season as a possible in-season arrival to the big leagues with the North Siders. The former prep baseball and basketball standout climbed through Double-A and Triple-A last season and launched a pair of home runs in the Futures Game to claim MVP honors and put his name on the national radar. He was selected by the Cubs in the second round of the 2018 Draft.

In 100 games last season, Davis slashed .260/.375/.494 with 19 home runs, 25 doubles and 53 RBIs between Triple-A Iowa and Double-A Tennessee. He struck out 118 times, drew 50 walks and scored 66 runs combined with the two affiliates. The outfielder was in camp with the Cubs as an invitee during Spring Training, but he was not in the Opening Day plans and began his season back with the Triple-A club.

Through 22 games this season, Davis slashed .195/.286/.299 with just two home runs and seven RBIs, striking out 31 times in 91 plate appearances. The outfielder last played on May 3, landing on the Minor League injured list due to the back ailment. The Cubs sent Davis to their Arizona complex to continue his rehab program, but persistent discomfort in his back and then legs, leading to surgical intervention.