LONDON – Arsene Wenger admits he is under pressure to sign big-name players, claiming Arsenal supporters will not be happy unless the club brings in someone of Lionel Messi’s status in January.Wenger has been linked with a £10 million bid for Atletico Madrid striker Adrian Lopez, while Crystal Palace’s 21-year-old England international Wilfried Zaha and Schalke midfielder Lewis Holtby are others understood to be on Wenger’s radar.However, while he is keeping one eye on the future, the Gunners manager is aware that fans are demanding to see players who can deliver immediate results."It is very difficult because the level of expectation is very high - people want to see Lionel Messi come in, they don’t want to see a promising guy,” said Wenger."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.”Wenger also revealed he made a straight choice between signing Demba Ba or Olivier Giroud last summer and insists he has no regrets about opting for the Frenchman."I like Demba Ba, but he is a similar type to Giroud who we just bought and it was one or other that we had to decide on,” admitted Wenger, who went on to give a positive slant on suggestions that Senegal striker may struggle to pass a medical due to his long-standing knee issue.Wenger went on to admit his drive to sign new players in this January transfer window may not be as easy as it was for him back when he first arrived at Arsenal back in 1996, when his network of scouts placed him a step ahead of many of his Premier League rivals in the race to sign the best overseas talent."The quality of scouting has improved and that is a big difference from when I first came to England,” he added.