Dominik Szoboszlai went off after 32 minutes in Liverpool's 2-1 win at Brentford after aggravating a hamstring injury, and Andoni Iraola said he will be out "for some time."
BBC Sport's Phil McNulty saw Virgil van Dijk wave his arms furiously at Liverpool's forwards in the first half at Brentford, before Liverpool came from 1-0 down to lead 2-1.
Brentford midfielder Yehor Yarmolyuk was sent off for violent conduct after moving his head towards Jérémy Jacquet, with Liverpool keeping a corner instead of getting a penalty.
Liverpool came from behind to beat nine-man Brentford 2-1, ending Brentford's unbeaten league start and moving above them in the table.
