LOS ANGELES – The Los Angeles Rams have opened the 21-day practice period for wide receiver Puka Nacua, the team announced Tuesday.

Nacua, who sprained his PCL (posterior cruciate ligament) in Week 1, has missed the Rams’ previous five games. The injury was an aggravation of a knee injury during training camp.

The window gives Nacua the opportunity to practice without coming off injured reserve; he now has 21 days to be activated for selection.

The Rams have been without their top two receivers since Week 2, but expect to get receiver Cooper Kupp back from a sprained ankle on Thursday night against the Minnesota Vikings.

Last season, Nacua set records for most receptions (105) and receiving yards (1,486) by a rookie in NFL history. Nacua had four catches for 35 yards in the Rams’ season opener before his injury.