Allen (quadriceps) is not listed on the Rams' injury report ahead of Thursday's game against the 49ers, Sarah Barshop of ESPN.com reports.
Allen missed a few weeks of action during training camp with the injury but is all good for the opener. The tight end appeared in all 17 regular-season games last season, finishing with career highs in targets (33), catches (24), yards (208) and touchdowns (three) on 52 percent of the Rams' offensive snaps. He's expected to again be part of Los Angeles' heavy tight end usage this season.