Los Angeles Rams star wide receiver Puka Nacua left practice early on Sunday and had his right knee wrapped in ice, The Athletic reported.

Nacua, 24, left a joint practice with Los Angeles Chargers after a series against their defense, then watched in full uniform from the sideline with a bag of ice on his knee, per the report.

After practice, Rams coach Sean McVay didn’t have an answer as to why last season’s runner-up in NFL Offensive Rookie of the Year voting exited early.

Following an off day on Monday, the Rams return to practice on Tuesday at their old facility in Thousand Oaks, Calif.

Nacua is coming off a stellar rookie campaign, with 105 catches for 1,486 yards and six touchdowns while starting all 17 games. A fifth-round pick, he made the Pro Bowl after setting NFL rookie records for receptions and receiving yards.

McVay and the Rams are practicing without a trio of starting offensive linemen: guard Jonah Jackson (bruised scapula) and tackles Rob Havenstein (foot) and Alaric Jackson (ankle), each of whom McVay has labeled as “week-to-week.”

–Field Level Media