Arsenal manager Arsene Wenger has said that the club's fans want him to sign a player of Lionel Messi's calibre.
The Frenchman claims that such high expectations during transfer windows can make his task of recruiting players to reinforce his squad difficult.
"It's very difficult because the level of expectation is very high," Wenger told Arsenal's official website.
"People want to see Lionel Messi. They don't want to see a promising guy.
"First of all the name gives hope. When a guy has no name people are already sceptical. So it's much more difficult for us."
Arsenal are currently sixth in the Premier League table.