Former Tottenham midfielder Dele was sent off on his debut for Serie A side Como after just 10 minutes on the pitch.
Dele - making his first appearance for 748 days - was initially shown a yellow card for raking down the ankle of AC Milan midfielder Ruben Loftus-Cheek but saw the incident upgraded to a red card following a VAR review, despite the protestations of Milan defender and Dele's former team-mate Kyle Walker.
Como boss Cesc Fabregas was also sent off for his reaction to the incident.
The 28-year-old joined up with Fabregas' side in the January transfer window after leaving Everton as a free agent but had not made an appearance prior to Saturday's San Siro fixture.
Dele started the fixture on the bench, as he had for the last two games against Roma and Venezia, but was brought on in the 81st minute.