J.J. Watt will be playing in the final NFL game of his career when the Arizona Cardinals take on the San Francisco 49ers on Sunday and he received a surprise on social media.

Pittsburgh Steelers players T.J. Watt and Derek Watt honored their brother J.J. when they wore his No. 99 Cardinals jersey ahead of their own game against the Cleveland Browns. The Arizona star reacted to his brothers in a tweet.

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The Watt brothers in 2020

T.J. Watt, left, and Derek Watt of the Steelers talk to their brother J.J. Watt of the Houston Texans after their game at Heinz Field on Sept. 27, 2020, in Pittsburgh. (Joe Sargent/Getty Images)

"Man oh man, I wasn’t ready for this this morning," he wrote. "Genuinely could not ask for two better brothers. 

"This means the world to me."

Watt joined the Cardinals in the 2021 offseason after spending his entire career with the Houston Texans. He played in seven games in 2021 and recorded one sack and 16 tackles. He looked more like himself in 2022 as he played in 15 games and recorded double-digit sack totals (10.5) for the first time since 2018.

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JJ Watt vs the Falcons

Arizona Cardinals defensive end J.J. Watt runs into the Falcons backfield, Sunday, Jan. 1, 2023, in Atlanta. (AP Photo/John Bazemore)

After 12 seasons in the NFL, Watt announced at the end of December he would be stepping away.

"Koa’s first ever NFL game," Watt said of his 2-month-old son, Koa James Watt. "My last ever NFL home game."

JJ Watt warms up

J.J. Watt of the Arizona Cardinals on the sidelines during the Falcons game at Mercedes-Benz Stadium on Jan. 1, 2023, in Atlanta. ( Todd Kirkland/Getty Images)

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He continued, "My heart is filled with nothing but love and gratitude. It’s been an absolute honor and a pleasure."

The Associated Press contributed to this report.