With a season-long loan for Liverpool’s Wales international Danny Ward being teed up, the 6ft 6in 20-year-old who has agreed a three-year contract with a further 12 months’ option in Town’s favour, may have to be patient.
But in time Coleman, who played 34 times for League I Oldham in the season just finished and has cost a reported £100,000, could be head coach Wagner’s first choice.
“Joel will challenge for the number one position with the potential to develop into a fantastic goalkeeper,” explained Wagner, who used Aston Villa loanee Jed Steer between the posts after his arrival as coach in November.
VIDEO: Coleman's fellow new arrival Chris Lowe
“It is unusual for a goalkeeper aged 20 to have Joel’s first-team experience (45 appearances in all) and he has shown lots of potential in his performances for Oldham, which we have watched closely.
“Obviously a goalkeeper must be excellent at the fundamentals of the position first - keeping the ball out of the net – but Joel’s ability with the ball at his feet is also ideal for our style of play.
“We’re all excited at working with him on the training pitch and in games for the next three years at least.”
Bolton-born Coleman joined Oldham as an 11-year-old and helped the Latics win the Lancashire FA Youth Cup in 2013-14.
He signed a two-year contract that summer (Oldham recently invoked a 12-month extension option) and made his debut as a substitute for Jake Kean in the 3-1 home League I defeat by MK Dons in March 2015.
Coleman kept the first of 17 clean sheets so far on his full debut in the following match at Crewe Alexandra, which his side won 1-0.
With Kean kept out, Coleman ended the season with 11 starts in total, and made 34 during the campaign just finished.
The return of Steer to Aston Villa and a shoulder problem for Joe Murphy, who will be out until October after surgery, has made signing two keepers a necessity for Wagner, who has released Lloyd Allinson, Sam Guthrie and Ed Wilczynski.