The 33-year-old striker collected a ?1.5million pay-off from the Hammers this week after having his contract terminated by mutual consent.
McCarthy was left out of Grant's 25-man Barclays Premier League squad for the second half of this season following the transfer-window signings of Robbie Keane and Demba Ba and admitted: 'I don't really know when I last spoke to him - but he's got a lot on his plate at the moment.
'I'm sure he could help his position if he had maybe taken a little bit more time to speak to players.
Axed: McCarthy had his West Ham contract terminated by mutual consent earlier this week
'That's what you do if you are a manager and you have a good relationship with players. You get results.
'But I'm not the type of person to go to a manager and give themultimatums - they make decisions on what they see in training.'
The South Africa international, who failed to score in his 14appearances after joining from Blackburn in January 2010, also tookresponsibility for his weight problems.
He told Sky Sports News: 'I let myself down. I just went hidingunder a rock because I couldn't deal with the fact that I was injured.
Hammer time: The South Africa striker has hit out at his former boss Avram Grant
'I never trained how I could train because obviously I was out fortwo months (with a calf injury) so I wasn't allowed to train oranything - it was just treatment, treatment, treatment.'
Meanwhile, West Ham striker Carlton Cole has accepted a charge ofimproper conduct in relation to comments he made on Twitter duringEngland's friendly against Ghana last month.
Cole tweeted during the 1-1 draw at Wembley: 'Immigration has surrounded the Wembley premises! I knew it was a trap! Hahahaha.
'The only way to get out safely is to wear an England jersey and paint your face with the St George's flag!'
Cole later withdrew the comments, but was still charged by theFootball Association. The former Chelsea player accepted the chargeyesterday and is now likely to receive a fine or a warning.
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Explore more:People: Benni McCarthy, Robbie Keane, Carlton Cole Places: South Africa, United Kingdom, Ghana