Cleveland Browns quarterback Johnny Manziel (2) warms up before the start of a game against the Seattle Seahawks at CenturyLink Field.(Photo: Troy Wayrynen, USA TODAY Sports)

LAS VEGAS — Johnny Manziel, who will sit out the Cleveland Browns' regular season finale Sunday due to a concussion, was seen Saturday dining and gambling at Las Vegas' Planet Hollywood casino, according to employees and patrons who interacted with the embattled quarterback.

Manziel, who Browns coach Mike Pettine said still must address off-field problems that resulted in a stint in rehab last year, paid cash for a meal at a restaurant in the casino, according to Tina Samira, a waitress who served Manziel and his guests at Heart Bar at Planet Hollywood.

Manziel also sat down at a blackjack table and a casino employee examining his photo ID exclaimed, "We've got Johnny Manziel with us tonight," according to John Hornacek, a 43-year-old casino patron who witnessed the exchange.

Manziel, 23, started six games in his second season with the Browns but was ruled out of Sunday's game on Thursday by Pettine, who said Manziel was in the NFL's post-concussion protocol. The Browns (3-12) play host to the Pittsburgh Steelers at 1 p.m. ET.

Cleveland Browns vice president of communications Peter John Baptiste would not confirm for USA TODAY Sports whether Manziel was in Cleveland, or if club policy dictated that an inactive player's attendance was required at Sunday's game.

Manziel's rookie season ended under dubious circumstances, when he overslept before the Dec. 27, 2014 season finale while partying with teammate Josh Gordon. Gordon, who had past violations of the NFL's substance abuse policy, was eventually suspended indefinitely, and Manziel entered alcohol rehab in February 2015.

As word of Manziel's presence in Las Vegas spread on social media, he posted a photo on Instagram showing him home with his dog, with the hashtag #SaturdayNights. He later added Avon, Ohio as the photo's location.