Arsenal are assessing Kai Havertz amid fears the striker could be set for a spell on the sidelines with a knee injury. The German came off the bench for the final 30 minutes of Sunday’s 1-0 win at Old Trafford, but was absent from an open training session at Emirates Stadium three days later.

Arsenal had an open training session at the Emirates on Wednesday before their first home fixture of the Premier League season when they host Leeds United on Saturday. Ben White and Kai Havertz were glaring omissions. White came off in the 71st minute in the win at Manchester United on Sunday and Havertz started the game on the bench.

Havertz' injury is expected to lead to Arsenal bringing in a new forward before the end of the summer transfer window, as a long-term absence would leave the Gunners short in the final third of the field.

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.

Havertz, who earns £250,000-a-week at the Emirates Stadium, was Arsenal's main man in attack last season, but he's since been joined by Viktor Gyokeres as another option for the centre-forward position. As a result, Havertz was on the bench against Manchester United at the weekend, with Gyokeres leading the line for the Gunners.

Leeds United started life back in the Premier League with a 1-0 victory over Everton at Elland Road on Monday night, and they take on Arsenal next at Emirates Stadium on Saturday. Leeds will be facing one of their fiercest oppositions this season this weekend given how impressive the Gunners have been in the last three seasons.