Arsene Wenger has slammed former Arsenal winger David Bentley and accused him of trying to unsettle Theo Walcott.
Blackburn star Bentley, who left the north Londoners in 2006 after five years having made just one appearance for the first team, has told Walcott he might need to quit the Emirates to find regular football.
But Wenger insists the youngster, who came on as a substitute for the last 19 minutes of the Gunners' midweek triumph against AC Milan and promptly made the second goal for Emmanuel Adebayor, can be a major star.
The Arsenal boss said: "Bentley is entitled to his opinion but it does not mean he is right.
"I don't know why one player should incite another player to leave a club. It is not his job. What is important is what the player really wants.
"When you are in one of the biggest clubs in the world you have to accept competition and if you accept it, it makes you better. If you move down you are down, not at the top.
"I believe Theo can establish himself here. He is 18 and at that age to play in one of the biggest clubs in the world in a regular position is very difficult.
"As a striker he has one big quality. When he comes on he makes a big impact. He's not there completely yet when he starts a game but that is transitional.
"Very soon he will have the same impact when he starts. You cannot interrupt that kind of progression and development of a player. You can get lost by moving.
"Between 18 and 20 a player develops. When I took Nicolas Anelka at 17 for the first few months he looked completely behind the team and then in three months he became in front of Ian Wright."
Walcott will miss Sunday's visit to Wigan after sustaining a slight thigh injury in a reserve match against Colorado Rapids at the Premier League club's training ground.