Elder spent last season on loan with the Latics, establishing himself as their first-choice left-back as they romped to the League One title.
The 23-year-old Australian was a key player in Wigan's run to the FA Cup quarter-final, too, scoring against Bournemouth and assisting Will Grigg's winner over Manchester City.
“Everything's a possibility at this time of year," Cook told the Wigan Post.
“There's so much that goes into deals these days – transfer fees, wages, agents, expectations – things do take time.
“And while we're not ruling anybody in, we're certainly not ruling anybody out.
“For what Callum's done at this club last year, he would certainly be on the list."