Following the Hammers' 5-1 defeat to Arsene Wenger's side on Wednesday evening, manager Sam Allardyce called his players in at 7:00 a.m. the next morning.
And Nolan has admitted that his Senegalese midfield colleague's tardiness had him concerned.
“Mo Diame was a bit late. When he arrived we all gave him stick. We said we thought he had left us without saying goodbye," he told reporters.
There is a lot of speculation in the media about Mo. To be fair to him, he took all the banter really well."
The former Bolton midfielder also expressed regret over his side's performance at the Emirates Stadium, adding: "We were all upset and disappointed with the result at the Emirates and I apologize to our fans.
“We are now focusing on the match at Fulham.”