With Major League Baseball looking into social media posts involving Tampa Bay shortstop Wander Franco, the 22-year-old All-Star did not travel on the team plane to San Francisco ahead of the Rays' series with the Giants, sources told ESPN.

"During today's game, we were made aware of the social media posts that are circulating regarding Wander Franco," the Rays said in a statement Sunday. "We take the situation seriously and are in close contact with Major League Baseball as it conducts its due diligence."

Tampa Bay did not detail the nature of the social media posts.

As MLB looks into the social media posts to verify the information, Franco could be placed on the restricted list or administrative leave. The Rays, when asked about Franco not being on the team plane, declined comment to ESPN.

Franco, who did not play in Sunday's game against Cleveland, was in the Rays' dugout at the beginning of the game, then left during the fifth inning. He did not speak to the media following Tampa Bay's 9-2 loss.

Sunday's promotion at Tropicana Field was the Wander Franco snapback hat for fans 14 and under.

After the game, Rays manager Kevin Cash was asked whether there was any issue with Franco not playing other than a regular day off. Cash replied: "No."

"I'm aware of the speculation, and I'm not going to comment any further on that," Cash said. "The day off was because [it was] a day off."

The Rays called up Osleivis Basabe to start at shortstop in his major league debut. Basabe, who went 1-for-3 with a double, learned he was being brought up during his game Saturday night with Triple-A Durham.

The restricted list, in which a player is taken off the roster and generally not paid, has been used by teams for a variety of reasons: treatment for substance abuse, arrests, failure to report, visa issues and at players' request to work through various issues. With administrative leave, which was used in the case of former Los Angeles Dodgers starter Trevor Bauer as the league was investigating domestic violence allegations against him, the player is taken off the roster but paid. MLB and the MLB Players Association must agree to place a player on administrative leave.

In November 2021, Tampa Bay signed Franco to an 11-year, $182 million contract, a deal that could be worth up to $223 million if a team option for 2033 is exercised.

Franco, who made his first All-Star team and is among the league leaders in wins above replacement this season, is hitting .281/.344/.475 with 17 home runs and 58 RBIs and is 30-for-40 in stolen base attempts in 112 games.

Earlier this season, the Rays benched Franco for "not being the best teammate," Cash said, in the way he handled his on-field frustrations.

The Rays begin a three-game series with the Giants on Monday.

Information from The Associated Press was included in this report.