Just days after Alex Rodriguez and Jennifer Lopez announced their engagement with a stunning image of a diamond ring, former baseball star Jose Canseco accused the Yankees' star of cheating.

In a tweet, the “Juiced” writer claimed Rodriguez cheated on his new fiancé with Canseco’s ex-wife, Jessica.

“Watching World of Dance watching J.Lo text Alex Rodriguez little does she know that he is cheating on her with my ex-wife Jessica poor girl she has no idea who he really is,” Canseco tweeted.

“I was there a few months back with her when he called her on her phone,” he added.

Canseco finished up the Twitter rant by challenging A-Rod to a fight.

“Alex Rodriguez I challenge you to a boxing match or an MMA match anytime you want,” he tweeted.

This isn’t the first time Canseco has made accusations against Rodriguez. In his 2008 book, Vindicated, Canseco alleged he introduced Rodriguez to a steroids supplier. He also claimed that Rodriguez showed interest in Jessica during the late 1990s.

A year after Vindicated was released, reports revealed Rodriguez tested positive for banned substances during a 2003 drug test.

After his tweets accusing A-Rod of cheating went viral, Canseco doubled down on the claims, tweeting that he could pass a polygraph about the allegations.

When it comes to Jose and Jessica’s relationship, the two have always had a bit of a tumultuous relationship. In 1997, Canseco was arrested and charged with battery for beating Jessica. He was sentenced to one-year probation as a result.

In her autobiography, Juicy: Confessions of a Former Baseball Wife, Jessica Canseco details cheating and abuse by Jose Canseco, writing, “the guy is an a-----e, but the perks are good.”