Tempe, United States: The Arizona Cardinals placed Carson Palmer on the injured list on Monday with torn knee ligaments, just three days after the star quarterback signed a lucrative $50 million contract extension.

The 34-year-old tore his anterior cruciate ligament (ACL) in his left knee when he was tackled by St Louis Rams player Mark Barron in the final quarter of the Cardinals’ 31-14 win on Sunday.

“It’s just a shame it happened now, with this team,” said Arizona coach Bruce Arians.

On Friday, Palmer signed a three-year contract extension with the first-placed Cardinals. Arizona did not release details of the deal but the US media reported it to be worth $50 million.

Palmer was scheduled to become a free agent at the end of the current National Football League season.

The Cardinals rewarded Palmer for leading them to a 7-1 record heading into the Rams game.

The team did now say how long Palmer would be out but the rehab is expected to be extensive.

Palmer, who missed three games earlier this season with a shoulder injury, had reconstructive surgery on the same knee in 2006 as a member of the Cincinnati Bengals. Both of his ACL tears came just days after signing contract extensions.