The 30 year-old Russian believes the team will need to adjust their playing style following the raft of new signings made by Arsene Wenger at the end of last month.
He told Russian newspaper Sport: "The loss of Fabregas and Nasri is very significant.
"When sitting on the bench during the Udinese game, I told Bendtner that we have no players who can feed van Persie or use the strong sides of other forwards. Bendtner said that only Xavi could have replaced Cesc.
"I'm glad I had the opportunity to play with such a great footballer. Some are irreplaceable."
He added: "With Arteta and other players in his position, we will play different football from that of Cesc and Samir period"
Arshavin said he doubted whether the team would be strong enough however to challenge Manchester City, Manchester United and Chelsea.
"It's difficult to say whether Arsenal can fight with the Manchester clubs and Chelsea, but those teams look very intimidating"Arshavin also praised new colleague Per Mertesacker but admitted to knowing nothing about defender Andre Santos, who joined the club from Fenerbahce.
"I know Mertesacker, he is a good defender, and he will help us.
"I don't know anything about Andre Santos apart from that he is a Brazilian international."
Furthermore, the 30-year-old admitted that his side could do with a further addition in midfield.
"We could use another defensive midfielder, but unfortunately the bid for Yann M'Vila [the France and Rennes midfielder] didn't work out."
Next up for the Gunners comes a home match against Swansea City, before they begin their Champions League campaign away to German champions Borussia Dortmund at the intimidating Westfalenstadion, a match which Arshavin is looking forward to.
"It will be interesting to play Dortmund in the Champions League. I've seen them play against Hamburg, and Gotze is amazing. That will make it a more curious game"