The South Africa international bagged 18 goals in the Premier League last season, immediately prompting a failed bid from Chelsea for the 29-year-old.
Blackburn chief Mark Hughes has insisted throughout that McCarthy will be lining up in a Rovers shirt again at the start of next season, but the Hammers have money to burn courtesy of owner Eggert Magnusson.
The former Porto frontman moved to Ewood Park for a bargain £2.5million last summer but is probably now valued at four times that amount, although whether that will be enough for Hughes' head to turn remains to be seen.
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