The Magpies are likely to go on a spending spree, as they hope to avoid relegation to the Championship.
Considering the financial might of their new owners, Newcastle are likely to put in big offers for players that they believe can strengthen their squad.
"I expect some action - absolutely," Shearer said about the transfer window on the CBS podcast Que Golazo.
"If that wasn't to happen then NUFC would be in big trouble.
"The owners have said there is money to spend - but Newcastle fans, pundits and former players, we're all going to have to be very patient because it's not going to happen overnight, or a month, it's going to take a long time - it's going to be small steps.
"It's going to be a certain type of player first and foremost to get Newcastle out of the relegation zone - then to entertain, players who are solid and committed to the football club and are prepared to give everything.
"There will be players who will be desperate to come to Newcastle United to prove themselves and to improve the squad because that is, without doubt, is what is needed."
He added: "We could do with plays straight down the spine.
"They've been poor defensively - one of the worst defences so it doesn't take a rocket scientist to work out what they need, they need a defender or two.
"Certainly a creative midfielder, and without Callum Wilson, his career will tell you he will pick up injuries every now and then and won't play every game, so they need another forward to put the ball in the back of the net to try and take the burden away from him for when he is and isn't playing.
"So three players without a doubt - a centre-half, a creative midfielder and a forward to put the ball in the back of the net."
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