Martin O'Neill has conceded he will need to be patient as he looks to attract players of the right quality to Aston Villa this summer.
Villa have already agreed a £5.5million fee with Chelsea for midfielder Steve Sidwell and continue to be linked with a host of other players, including Spurs striker Darren Bent and former loanee goalkeeper Scott Carson from Liverpool.
But with O'Neill yet to add to his wafer-thin squad this summer and speculation suggesting Gareth Barry is close to joining Liverpool, the Villa boss has admitted he will need to bide his time before concluding any transfer business.
"It takes a bit of time," he told the club's official website. "We've got targets in mind, of course and want to do business as promptly as we possibly can.
"But the people we want to try and improve this club are players you can almost automatically assume are key players at other football clubs.
"These are people it might be difficult to prise out of their current clubs.
"We need to improve our squad and I know that, but it's a fact that improving the squad gets harder as you progress.
"We've just finished sixth in the Premier League and I think the supporters will agree that we have progressed over the last two years.
"To improve on what we now have means bringing in even more quality - the competition for quality players can be fierce."