Robbie Keane believes Andrey Arshavin still has much to learn about the Premier League.
The two players meet when the Republic of Ireland take on Russia in a pivotal Euro 2012 qualifier at the Aviva stadium on Friday night.
And Tottenham striker Keane insists the Arsenal playmaker may find life tougher following 12 goals in his first full season at the Emirates.
He told the Daily Star: "It will be a big test for him this year.
"The second season is always more difficult."
The White Hart Lane forward is in confident mood ahead of the clash in Dublin following Ireland's perfect start to the qualifying campaign.
Giovanni Trapattoni's side defeated Armenia and Andorra last month while the Russians were unimpressive in victory over the latter before slipping to a shock home defeat to Slovakia.
Keane said: "We're not going into the game just worried about Arshavin.
"Russia should be worried about the players we have, people like (Aiden) McGeady and (Liam) Lawrence."