Jrue Holiday made his debut with the Celtics on Wednesday night, kicking off his 15th NBA season.

Holiday’s new Boston teammate Jayson Tatum greeted him warmly, but had to give him a reality check when they talked before tip-off against the Knicks.

“You’ve played against T-Mac [Tracy McGrady] and with me. “You’re getting old, my bro,” Tatum said.

McGrady retired in 2013 after a 16-year career. He was drafted one year before Tatum was born, which explains why it was difficult for the Celtics star to fathom.

Holiday, 33, isn’t the oldest active NBA player (that honor is held by 38-year-old LeBron James this season), but he does join a young Celtics team. Even so, Holiday isn’t the Celtics’ oldest player—Al Horford is 37.

Holiday was moved to Boston after being dealt to Portland from Milwaukee as part of the Damian Lillard transaction.