At the end of the 2015-16 campaign, Newcastle were relegated to the second tier but since then, the Magpies have won the Championship title as well as registering 14 points from their first 11 games in this season's Premier League.
There was much disappointment at St James' Park when they dropped out of the top flight in May 2016, but Shelvey has suggested that it was a blessing in disguise for Rafael Benitez's men.
The 25-year-old is quoted by Chronicle Live as saying: "Last year, I think the club needed that, to be fair – to drop down a league and get that spine back to this football club.
"It was a good time, last year. We had a lot of fun in the team and we just tried to continue that team spirit over the summer. We're always chatting on the WhatsApp group and doing dinners and things like that. There's a great team spirit.
"Everyone in this squad works for each other – you'll run that extra 10 yards for your team-mate, because we've got such a good bond. I think that started since Rafa came into the fold. He bought players last year that knew that league and had that team spirit and togetherness. I think that's what got us promoted. We've got to keep maintaining that."
Newcastle have lost their last two fixtures to drop down to 11th place in the standings.