The 36 year-old has received the same feedback from Everton manager David Moyes as he considers his options this summer.
Coleman is expected to extend his contract for another 12 months with Everton, though his international future is clouded.
"He is a leader in this squad and you cannot have his experience in many players," Hallgrimsson told reporters on Thursday.
"His experience, his leadership skills are one thing, but his quality as a player is another thing as well.
"He's been playing at the highest level for such a long time, so it's a shame for me - and, of course the national team - not to have him around. But hopefully there will come another time for him, hopefully it will be just the off-season and he'll come fit and flying."
Everton plans in place
Hallgrimsson also said: "I know he's going to be at Everton in whatever role, maybe a little bit more leadership role, but it's for him to answer if he's going to continue playing or not.
"It's his decision, but I'm hoping - and I know the Evertonians are hoping - he will continue playing."