Top Red Sox pick Marcelo Mayer expected to make his pro debut Thursday

Marcelo Mayer opted for the Red Sox instead of Southern Cal, where he was committed, after Boston took him with the No. 4 pick in last month's draft.John Tlumacki/Globe Staff

At 10 a.m. on Thursday morning, shortstop Marcelo Mayer will play his first official game as a member of the Red Sox. The team’s first-round pick, and the fourth player taken in the 2021 draft, is expected to make his pro debut in the Florida Complex League, according to a major league source.

Perhaps Mayer will make an immediate mark, as Rafael Devers did in the Dominican Summer League on May 31, 2014, when he went 3-for-5 with an opposite-field homer — almost unheard of in the DSL — in his professional debut. Perhaps he’ll endure a moment of infamy, as Mookie Betts did when committing three errors in his pro debut in the Rookie Level Gulf Coast League on Aug. 26, 2011.

The Sox will read little into the results this year either way as Mayer, taken out of Eastlake High School in Chula Vista, Calif., acclimates to professional baseball. Still, his debut is the source of considerable excitement for an organization that hopes Thursday marks the start of an ascent toward a long future in the big leagues.

Mayer’s smoothness earned comparisons this spring to Dodgers All-Star shortstop Corey Seager at the plate and Giants Gold Glover Brandon Crawford in the field. Many saw him as the top talent in the draft.

The Red Sox signed Mayer for a $6,664,000 bonus last month, the MLB slot recommendation for the No. 4 overall pick.