Aston Villa defender Richard Dunne has warned James Milner he might not be guaranteed a place in the team if he leaves for Manchester City.[LNB] Republic of Ireland international Dunne joined Villa from City last summer as the world's richest club flexed its financial muscles and he became surplus to requirements.[LNB]They are preparing to spend again, with £20million-plus-rated Milner firmly in their sights, although his club-mate has warned the blossoming England midfielder the grass may not necessarily be greener in the blue half of Manchester.[LNB]Dunne, 30, said: "Manchester City is a really big club now, but I suppose the problem they will have is they will have a lot of top players - £20million is nothing to them.[LNB]"It's just another player really, so it's whether you are going to get enough game time.[LNB]"But I am sure with James, he is a very, very sensible fella and very clever, so he will make his own decision."[LNB]Milner has established himself as one of the English game's rising stars since his £12million switch from Newcastle to Villa, and the 24-year-old played a major part in the club's sustained challenge for a top-four finish last season.[LNB]For that reason, Villa are desperate to hang on to him amid concerted interest, although Dunne knows money could eventually talk.[LNB]He said: "That's the big thing. We want to progress as a club, but there are always bigger clubs, I suppose, with more money who can offer him maybe Champions League football, so it will be difficult.[LNB]"But if things don't work out and James does have to leave, the manager has been really good in the transfer market and will spend his money well.[LNB]"We have already got the likes of Fabian Delph there, who is going to become a really good player.[LNB]"As much as we want to keep James, we know we he is a much sought after player and it might prove difficult."