Manager Arsene Wenger has to choose between Germany's Jens Lehmann or Manuel Almunia following the Spaniard's error-prone display at Highbury on Tuesday.
Almunia was at fault for Rosenborg's goal when he failed to deal with a flighted free-kick and also made a bad mistake in the first minute against Manchester United last week which cost Arsenal dearly in a 1-0 League Cup defeat.
Lehmann, between the posts during Arsenal's record unbeaten league run, was dropped for the first time at the weekend against Birmingham City and Wenger must now decide whether to choose Lehmann's experience over Almunia's potential.
"I will leave that (choice) open to Sunday," said Wenger. "I never said that Almunia would play against Chelsea, I said we would take it game by game.
"I am a great believer in Almunia's potential but he plays under such a big pressure. A goalkeeper knows every small mistake is analysed, every small mistake becomes a big problem."
Wenger will find Chelsea and their rampant attack far more formidable opponents than a poor Rosenborg team who were well beaten inside the first half an hour with goals from Jose Antonio Reyes, Thierry Henry, and Francesc Fabregas.
FLAIR PLAYERS
Fabregas, deputising for Patrick Vieira who is also suspended against Chelsea, was excellent throughout and Justin Hoyte - in for the suspended Lauren at right back - and striker Mathieu Flamini also showed flair.
Victory sealed Arsenal's place in the draw for the last 16 knockout round on December 17 at UEFA's Swiss headquarters.
The infusion of youthful energy seemed to inspire Arsenal who have rarely sparkled since United's 2-0 league victory in October ended the London side's record 49-match run.
After leading the table for most of 2004, champions Arsenal are now five points behind rampant Chelsea and cannot afford to lose on Sunday.
"The youngsters showed they are old enough, they showed a lot of qualities," said Henry. "Now we can concentrate on Chelsea.
"I don't know if the bad spell is over. When you are not playing as well as you can, you can only rectify it on the pitch."
Vieira's absence and injuries to Brazilians Edu and Gilberto have left Wenger with problems in midfield against Chelsea and he will need Freddie Ljungberg who missed the Rosenborg match after suffering what Wenger called a "huge" migraine headache.
He was sent home from Highbury and is doubtful for Chelsea's visit, potentially a decisive 90 minutes in the English title race.
