Gillespie initially left the Magpies as a youngster in 2008 when was 16 years old, and subsequently linked up with Carlisle United.

After progressing through the ranks at Brunton Park, he became the youngster ever goalkeeper to represent the Cumbrians - at the age of 18 years and 42 days - when he came off the bench for his League One debut against Norwich City in May 2010.

Having enjoyed a spell on loan at Blyth Spartans in 2010/11, he returned to Carlisle and displaced former Newcastle youngster Adam Collin between the sticks, going on to make 180 appearances for the Blues before leaving for Walsall in 2017.

A year later, Gillespie moved on to Scottish Premiership side Motherwell, helping his new club finish third in the 2019/20 campaign.

And his impressive form saw him brought back to St. James' Park on a three-year contract, with his long-awaited debut for the club coming in a 1-0 League Cup win over Blackburn Rovers at St. James' Park in September 2020.