Since Michael Laudrup left the Liberty Stadium in February 2014, Swansea have parted company with four permanent managers, with Carlos Carvalhal recently being brought in as a replacement for Paul Clement.
Shelvey made 98 appearances for the Swans between July 2013 and January 2016, but the England international feels that the Welsh side have struggled for consistency due to the frequent alterations in the dugout.
The 25-year-old told NUFC TV: "They have chopped and changed the managers to be fair and I don't think that has helped them. I think they need to get back playing the way they played football.
"Even when I was at Liverpool you wouldn't see the ball for a lot of the time. When I went there everything was about ball possession, all of our work was about the football and we were battering teams at home with the ball - even against the top teams.
"They have gone away from that a little bit which is obviously down to whatever manager they had in at the time."
Shelvey could feature when Newcastle host Swansea in the Premier League at the weekend.