Arsène Wenger has admitted it is becoming more difficult to sign potential stars of the future due to pressure from supporters and scouts for big names to be brought to Arsenal.

Wenger's reputation for unearthing talent at a cut price is arguably the best in the Premier League, the manager having turned a number of players into top-class internationals since he was appointed by Arsenal in 1996.

Patrick Vieira signed from Milan for £3.5m and went on to inspire the north London club to seven major trophies, and Nicolas Anelka and Cesc Fábregas also arrived for nominal fees. The £10m spent on Thierry Henry in 1999 was regarded as a risky amount for a relatively unknown winger.

Wenger, who said that any incomings during the January transfer window were not a priority until Theo Walcott agrees to a contract extension, believes the arrival of such gems is more unlikely in the modern era. Asked how tough it is to make decisions on incoming players, he said: "It's very difficult because the level of expectation is very high."

"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 play at Swansea City in the FA Cup third round on Sunday and Wenger will hope his defence can snuff out the threat from Michu, whom many consider to be the signing of the season following his £2m arrival from Rayo Vallecano last summer.

"We had heard of him," said Wenger. "He was a guy who disappeared a little bit. He was in clubs where he was bombed out and so you always think: 'OK, he doesn't make it there, why should he make it here?' But he has done extremely well. He looks as well that it is not accidental what he is doing, that he is a really good player.

"We have some other clubs who are doing very well and sometimes when you are a big club your scouts are a bit more cautious because they think: 'Oh, it is Arsenal, it has to be a top-four player.' So naturally they are less looking at players who play at smaller clubs, which Swansea can afford to do. You are always scared that he is a player who, if he does not do well, the scouts are looked at as responsible. The competition is higher on the scouting front, that is for sure."

The Frenchman added: "The country where we were really, really competitive was France. They produce less players than they did 10, 15 years ago at the top level. The emerging countries now look to be Germany and Spain and they have many good young players; they have taken over."

Wenger said Arsenal will let Sébastien Squillaci and Johan Djourou leave the club before the start of next week, and confirmed that the Schalke midfielder Lewis Holtby has caught his eye, although Tottenham have also been linked with a move for the 22-year-old.

Demba Ba, who is expected to complete his transfer from Newcastle United to Chelsea soon, was also under consideration by Arsenal, but Wenger opted instead to sign the French striker Olivier Giroud.

Squillaci is keen to return to France. The defender told Var-Matin: "I am experiencing this situation which I am not enjoying. Given offers, I will leave, possibly during the window or else I will wait until June. Marseille, Nice, Monaco, Ajaccio and Bastia are the clubs who are talking to me. I am 32, I have two or three good seasons left in me."