The Red Sox played their first MLB-on-MLB spring training game on Saturday, and left a lot of excitement in the air as prospects fueled their 6-4 win over the Tampa Bay Rays.

Many of Boston’s bona fide major league stars had the game off; Alex Bregman and Garrett Crochet are both slated for their debuts on Sunday. But Saturday provided the Red Sox’ first real opportunity to assess their young stars in spring training action.

Here are four highlights from Saturday’s matchup.

Ceddanne Rafaela claimed Boston’s first home run of spring training, driving a fastball deep over the left field wall in the top of the third inning.

Rafaela is looking to improve his offense ahead of the 2025 season. He noted postgame that his “plan is to walk more [and] swing at better pitches.”

On top of his more calculated approach, it appears Rafaela altered the mechanics of his swing, dropping his hands lower compared to last season. If that is the case, his early home run will surely fuel some confidence in his change.

Marcelo Mayer made his presence felt offensively on Saturday.

Despite the 1 for 4 official stat line, Mayer did plenty of heavy lifting at the plate. He drove home an RBI drew a walk and hit a rope to the gap in left-center that likely would have dropped in for a base hit nine out of 10 times. Unfortunately for Mayer, Rays center fielder Chandler Simpson made a beautiful diving catch to rob Mayer.

Mayer has a less clear path toward Boston’s Opening Day lineup, with Trevor Story holding down the Red Sox at shortstop and plenty of stiff competition — and drama — elsewhere in the infield.

Still, Mayer took advantage of the spotlight Saturday’s spring training game shined on him.

Boston moved Kyle Teel as a key figure of the Garrett Crochet trade with the White Sox, and also didn’t re-sign Danny Jansen, meaning Alex Cora will be looking for a backup catcher to add to the 40-man roster.

Carlos Narvaez made a strong case for that role on Saturday. The former Yankees prospect went 1 for 3 at the plate, and defensively showcased a quick pop out of his stance on two different occasions against the Rays.

Narvaez spent most of 2024 in Triple-A, where he held a .254 batting average. He’s currently battling Blake Sabol for the backup catching role behind Connor Wong.

Luis Guerrero has only appeared in nine MLB games in his career.

However, the 24-year-old could find himself a spot on Boston’s Opening Day roster in the bullpen, especially considering the injuries that group is battling.

Guerrero had a productive outing on Saturday, recording three strikeouts in his inning of work. He’ll have plenty of work to do in order to cement a spot for himself, but Boston has two pitchers likely to miss Opening Day, meaning they’ll need extra reinforcements for the first part of the year.

Guerrero could be a beneficiary of the Red Sox’ bullpen misfortune; his fastball looked dialed in on Saturday afternoon.