The Magpies were beaten 2-1 by Watford on Saturday afternoon.
The Magpies were beaten 2-1 by Watford on Saturday to leave them 18th in the table and two points from safety.
Scoring goals has very much been the problem for Steve McClaren’s side this season, with them only having managed 25 goals in 23 games so far, the 6th worst record in the division.
It was a similar story against the Hornets as they managed to get just two of their 11 shots on target in the game, and Shelvey has called upon them to find their ruthless streak sooner rather than later.
“We have to take our chances,” he told nufc.com. “We need to be more ruthless in front of goal. If we were more ruthless, we would have beaten them easily.
"We can create chances - we've got players throughout the team who can do that - but we have to be able to put those chances away."
If Newcastle are aiming to discover their ruthless streak in the second half of the campaign, a striker must be top of their shopping list in what remains of the January transfer window.
One solution could be Loic Remy, who is available from Chelsea, and has already proved his prowess at St James’ Park before, having scored 14 Premier League goals during a loan spell in 2013/14.
That is the kind of prolific striker this Magpies side could do with to aid their fight against relegation, and they could certainly do worse than him at present.