Arsenal will be without key defender Bacary Sagna for the crucial games against Napoli and Manchester City, reports Goal.com.
The Gunners' first choice right back has failed to recover from the hamstring injury that kept him out of the game against Everton on Sunday.
Unfortunately for Arsene Wenger, it is believed that Sagna's injury is worse than initially feared and he is unlikely to feature in the crucial Champions League and Premier League fixtures.
That means that 21-year-old Carl Jenkinson is likely to deputise in his place for Wednesday's game against Napoli, where Arsenal must avoid a 3-0 defeat to seal their place in the second round.
A point will guarantee top spot in the group of death that also contains Borussia Dortmund and Marseille.
Arsenal will then face Manchester City at the Etihad four days later, bringing an end to a congested fixture list.
The Citizens have won all seven of their homes games so far this season scoring 29 goals in the process.
Although Jenkinson has proved himself capable of performing in the Premier League, Arsenal will bemoan the fact that the experienced Sagna will be missing from the league's most successful defence.