The 23-year-old Wales forward has scored 11 goals during his season-long loan at Portman Road from Premier League side Leicester City.
"I think Tom will have his heart set on the Premier League and I think he'll get that," said McCarthy.
"If Leicester are going to sell him, there'd be a lot of takers."
He continued to BBC Radio Suffolk: "Tom has been brilliant and we've all loved him, everybody's really appreciated what he's done, but I think he has his heart set on Premier League football and why wouldn't he?"
The Tractor Boys were assured of Championship safety thanks to Easter Monday's 3-1 defeat of promotion hopefuls Newcastle United.
And McCarthy hinted that there could be a large turnover of players this summer as the club go into their 16th consecutive season in England's second tier.
McCarthy said: "It's been tentative before being completely safe. I'll sit down and talk to (owner) Marcus (Evans) now about what we want to do and hopefully we can come up with something.
"But there's a real opportunity to freshen it up because there are a lot of players out of contract and we've quite a few players on loan.
"Do they want to stay? Do we want them? Can we have them? Can we sign them? There's all those things. We'll be losing a few players."

The government has moved responsibility for its funding to the BBC, which the Defence Committee said had "entirely predictably" led to cuts.
It added that BBC Monitoring was "vital" to diplomacy and business.
The BBC said it was "confident" the service would continue to meet the UK government's needs.
The government directly funded BBC Monitoring until 2013, when responsibility passed to the BBC under an agreement announced by Chancellor George Osborne in 2010.
The cross-party committee said this had left the service exposed, with around 100 jobs set to go under a re-structuring programme.
It expressed concern at plans to move Monitoring out of its current Caversham Park headquarters in Berkshire, where it operates alongside US counterpart Open Source Enterprise, because of potential disruption to information-sharing.
Currently, Monitoring covers 25% of the globe, while Open Source Enterprise covers the remaining 75%.
The committee's report said: "The government uses open-source information for indicators and warnings of areas of instability and potential threats to UK security.
"The decisions made concerning the funding and governance of BBC Monitoring over the past decade or so have been woefully short-sighted and catastrophically ill-thought-out.
"A service that has the potential to be a vital tool in opening the world to UK diplomacy and business is in grave danger of becoming a hollow shell of its former existence."
A BBC spokeswoman said: "The media landscape has changed vastly since the creation of BBC Monitoring in the 1930s and we believe our planned restructure is vital to equip us for a world in which digital skills are far more important than physical location.
"We are confident that we will continue to meet the UK government's needs for open-source monitoring and they have told us they are happy with our changes."

He last played in September and was put on a training regime after being ruled unfit and overweight.
"I have had a good, constructive talk with Tony and the senior management and we all agree this is the best way forward for me," said the 23-year-old.
Baggies boss Tony Pulis has said that Berahino is "close" to a return.
The former England Under-21 international's form has suffered since he reacted angrily to a bid from Tottenham being turned down on transfer deadline day in summer 2015.
He scored seven times in 35 games last season, compared to 20 goals in 45 appearances in 2014-15, after threatening to not play for club chairman Jeremy Peace.
"This last year has been the most difficult of my career and it has left me short of the form and fitness required for the Premier League," said Berahino.
"I have never been a player who lacked confidence or a belief in himself but that has been where I have found myself and it has hit me hard.
"It has left me feeling depressed and struggling for focus which has made it even more difficult to regain full fitness."
In a statement, the club said it hopes the "change of environment" at the camp in the south of France will help Berahino return to full fitness.
West Brom host Burnley in the Premier League on Monday with full commentary available on BBC Radio 5 live from 20:00 GMT.
Championship side Ipswich Town have "no chance" of signing on-loan top scorer Tom Lawrence on a more permanent deal, according to manager Mick McCarthy.
[NEXT_CONCEPT]
BBC Monitoring, the UK service that translates and analyses global media, is in danger of becoming a "hollow shell", MPs have warned.
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West Brom striker Saido Berahino says he is in a positive frame of mind despite being sent back to a conditioning camp in France.