Major League Baseball’s sign-stealing investigation will reportedly expand beyond the Astros, as allegations against the Red Sox have thrust Boston into the spotlight.

The Athletic reported Tuesday that some Red Sox players in 2018 used the team’s video room to learn opponents’ sign sequences, which would directly violate Commissioner Rob Manfred’s late-2017 edict on sign-stealing.

“The Commissioner made clear in a Sept. 15, 2017, memorandum to clubs how seriously he would take any future violation of the regulations regarding use of electronic equipment or the inappropriate use of the video replay room,” MLB said in a statement to The Athletic. “Given these allegations, MLB will commence an investigation into this matter.”

The Red Sox were fined in 2017 for allegations that they had used an Apple Watch to try stealing signs against the Yankees. According to The Athletic, Manfred said he received “absolute assurances” from the Red Sox that they would not take part in illegal sign-stealing activity again.

Per the report, MLB sent a three-page memo to all 30 club presidents, general managers and assistant GMs prior to the 2018 season that stated “electronic equipment, including game feeds in the club replay room and/or video room, may never be used during a game for the purpose of stealing the opposing team’s signs.”

The report cites three people who were with the Red Sox during their World Series winning season in 2018 who said players were visiting the video room -- which is located just steps from the home dugout at Fenway Park -- to learn the sign sequence opposing teams were using. It also states that this type of scheme would not have been possible during the 2018 postseason, as there were monitors assigned to every replay room to prevent such behavior.

MLB has been investigating the Astros since November, when The Athletic reported on Houston’s alleged sign-stealing system that included banging on trash cans to relay signs that had been detected by a center-field camera.