On Monday, after the Ravens embarrassed the Rams 45-6 on Monday Night Football, Peters engaged in a verbal altercation with cornerback Jalen Ramsey, whom the Rams acquired only hours after trading Peters away. Then, as Peters made his way up the L.A. Memorial Coliseum tunnel to the visitor's locker room, he hollered a choice phrase in the direction of his former team.
"Kicking the Rams' ass out of the playoffs," Peters yelled.
The loss dropped the Rams to 6-5 and delivered a massive blow to their playoff chances a season after they appeared in Super Bowl LIII. The Ravens improved to 9-2 and are among the favorites to appear in Super Bowl LIV.
After the game, broadcast cameras showed Peters hugging a Rams staff member when Ramsey approached. The two engaged in a verbal altercation that required security and staff to intervene and separate them.
Ramsey would not entertain questions about the exchange after the game.
"If you've got questions about the game, I'll answer that," said Ramsey, who had one pass deflection and eight tackles. "Other than that, I ain't going to answer no B.S."
After his exchange with Ramsey, Peters eventually retreated to the visitors locker room while delivering a profanity-laced rant to no one in particular. Rams cornerbacks coach Aubrey Pleasant attempted to greet him, but Peters brushed him aside.
Peters was not among the five players brought to the Ravens' postgame podium to address reporters.
Peters finished Monday with eight tackles and intercepted a pass from quarterback Jared Goff. The interception was his third in five games with the Ravens.
"Yeah, that one, yeah," Goff said, shaking his head and trailing off when asked about Peters' pick. "He's a great player. Marcus is one of my favorite guys I've played with, and he made a great play."
Asked what the game meant for Peters, Ravens linebacker Matthew Judon replied, "Everything, man. He wanted to come in and get this win. You always do when you go back home.
"I don't care if I go back to Grand Valley. If I'm playing against them, I want to whoop them. ... For him to get that pick late in the game really killed the momentum. Really killed everything -- they had a little bit of momentum, they was getting first downs, and Pete came up with that huge pick, and he going to let you know about it. We love that guy in the locker room."
"Marcus out there doing what he does best," said running back Todd Gurley, who was among Peters' closest teammates during his 20-month stay in L.A. "He going to make his presence known. He going to make you pay for it. That's kind of what he did tonight."
With no intention of signing him to a long-term contract, the Rams traded Peters to the Ravens last month in exchange for a fifth-round pick and linebacker Kenny Young. Later the same day, the Rams sent two first-round picks and a fourth-round pick to the Jacksonville Jaguars to acquire Ramsey, who is in the fourth season of his five-year rookie deal.
After he arrived in Baltimore, Peters, who is in the final season of his rookie contract, told reporters that the trade surprised him, but he left "with his head held high."
The Rams have said that their intention is to sign Ramsey to a long-term deal. Widely considered among the top cornerbacks in the NFL, Ramsey is expected to command a record-breaking contract.