It is a big blow for the Premier League title contenders, with Havertz missing 12 league matches last term between February and May last season due to a hamstring problem. Ornstein claims the Gunners recruitment chiefs are exploring the transfer market to potentially reinforce their attack and cover the absence of Havertz.

Brighton will be the visitor on Sunday for the start of a new era for Everton, which — on the field — began the season in miserable fashion with a 1-0 loss at Leeds on Monday.