"I think there will be lots of eyebrow-raising deals done in January when fans in general will perhaps be surprised at the sums being paid for players but that just underlines what is at stake," McNally told British media.
"We have always made it clear we will spend what we can afford and we have a budget we will stick to. That has always been the case here.
"We will use our bank facilities as much as we can and I can promise we will be ambitious, as much as we can, but we won't be reckless."
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McNally also made it clear that manager Alex Neil does not need to offload players to attract fresh blood.
"If anybody is close to Alex's team and he intends to use them then I doubt they will be leaving the football club," he said.
"We are not under any pressure and Alex is under no pressure to offload players, however, if we bring in a few, let's say two or three, that adds to the roster and probably takes you over 25.
"You can only register 25 in a Premier League squad so, quite frankly, there might be some players who for themselves and their careers want to go elsewhere if they are not in the plans here."
Norwich will hope to steer clear from the relegation zone when they host 12th-placed Southampton, who have lost five times in their last seven games, in the league on Saturday.
(Reporting by Shravanth Vijayakumar in Bengaluru; editing by Sudipto Ganguly)
