Dallas Cowboys' star Micah Parsons meeting with Boston Celtics' star Jayston Tatum (left). Tatum and Parsons smiling (right).
Boston Celtics’ superstar Jayson Tatum obviously did his homework on Micah Parsons ahead of Wednesday’s game against the Miami Heat.

The Cowboys’ star edge rusher attended Game 1 of the Eastern Conference Finals between the Celtics and Heat at TD Garden on Wednesday. A pre-game video of Parsons and Tatum acknowledging one another on the court went viral, and there was a humorous twist in it.

Parsons shook hands with Tatum and hugged him, offering him the best of luck for the evening. An observant and wise Tatum told Parsons, “Last time I seen you, you had a Philly jersey.”

Tatum proceeded to ask Parsons who he was rooting for, and the Dallas superstar insisted that he was cheering for Boston.

In case you want proof of Tatum’s claims, here is a video of Parsons wearing a Philadelphia 76ers jersey during the team’s second round matchup against Boston:

The Celtics defeated the 76ers in a thrilling back-and-forth series to earn a second consecutive trip to the conference finals. Tatum went off in Game 7, racking up a game-high 51 points in Boston’s 112-88 blowout victory.

Philadelphia wound up relieving head coach Doc Rivers of his duties following the loss. Boston, enjoying its fourth conference finals appearance in six years, dropped Game 1 to Miami on Wednesday night.

Game 2 between the Heat and Celtics goes on Friday night at TD Garden at 8:30 p.m. ESt.