The Los Angeles Rams' Super Bowl title defence has become significantly more difficult with star wide receiver Cooper Kupp heading to injured reserve.

Coach Sean McVay told reporters on Tuesday that the 2021 AP Offensive Player of the Year will undergo tightrope surgery for his high-ankle sprain.

The recovery time is expected to be about five to six weeks, meaning it is possible Kupp could return for one of the Rams’ final few games.

It is also possible, however, the Rams ultimately decide to shut him down for the rest of the season if they are out of the playoff picture.

The Rams fell to 3-6 after Sunday’s 27-17 home loss to the Arizona Cardinals.

Kupp was injured against the Cardinals when he jumped in an attempt to make a catch and his right ankle was rolled over by a defender upon landing.

He has been one of the few bright spots in the Rams offence, ranking second in the NFL in receptions (75) and fifth in both receiving yards (812) and receiving touchdowns (6).

"Obviously you never ever replace a player like Cooper Kupp, but we've got to figure out the best way to accentuate the skill sets of the guys that will be playing," McVay said.

In 2021, Kupp became just the fifth player in the Super Bowl era to lead the NFL in receptions, receiving yards and receiving touchdowns.

He played a crucial role in the Rams’ run to the Super Bowl, catching 33 passes for 478 yards and six touchdowns in four playoff contests, including eight receptions for 92 yards and a pair of TDs in the title game.

Although he is enjoying another stellar season, the Rams rank 29th in scoring (16.4 points per game) and 31st in total yards (282.7 per game).

Allen Robinson and Van Jefferson will likely see larger roles in the offence in Kupp’s absence.