The goalkeeper joined Shrewsbury in June 2014 after leaving Blackpool, his home town club.
Mark once played in the Premier League for the Tangerines, coming on as a sub against Chelsea, but first team chances were hard to come by at Bloomfield Road owing to the consistency of Matt Gilks, a former Shrewsbury loanee.
Mark had loan spells away from Blackpool with Burscough, Hyde, Kettering, Barrow and Stockport County before joining Town on an initial 2 year deal.
Halstead made only one league appearance in his first season at the club, as a substitute, but went ton to make 16 league appearances in the 2015/16 season, plus a further three in the FA Cup- keeping a clean sheet against Cardiff City in the 3rd round.
He signed a new one year deal in the summer of 2016 and is hoping to nail down a first team spot.