The Championship side have been interested in the Republic of Ireland international this summer, but the Bluebirds boss believes he hasn’t got the financial muscle to get a deal over the line.
McCarthy worked with Curtis when he was boss of the Boys in Green, but feels Pompey’s valuation of the man also being linked with Blackburn makes a transfer a no go.
He told Wales Online: ‘We haven’t got the money to buy him.
‘What is he, £3m? We’re not buying him. We’ve not spent anything this summer.
‘We’ve gone with Mark McGuinness, who I think is a really good signing. He has started really well and I’m delighted with that.
‘Then we took a loan player and frees. James Collins is a great free for us - as Ryan Wintle will prove to be.
‘But we’ve not splashed the cash and we’re not going to do it now.’
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