Voss was inspirational in his last game as captain on Saturday night at the Gabba, throwing himself into the contests and gathering 34 possessions in a 51-point loss to St Kilda.
Matthews believes Voss is capable of seeing out the final year of his contract - but doesn't see him doing so in the forward position often occupied by contemporaries such as James Hird, Nathan Buckley or Mark Ricciuto.
Numerous commentators have suggested Voss could be played almost exclusively inside the forward 50m to ease the load on his ageing and sometimes aching body.
"I think Vossy is a midfielder and that's where he will finish his career. We haven't played him forward for lengthy periods of time but the periods that we have played him forward, I don't think it suits his physical capabilities," Matthews said.
"He has lost a fair bit of pace - everyone knows that - but he's still able to pound in and get the ball in the confined areas, whereas up forward you tend to have to move to the ball - 30 or 40m of hard running.
"We've never played him there (forward) a few weeks in a row to find out but I've heard and read that (the suggestion Voss should play forward) and from what I see of Vossy as a footballer he's still capable of being a good midfielder. I don't know if he's capable of being a forward 50m player any more."
Matthews is happy to leave any decision on retirement in Voss' hands and says he won't be putting pressure on the Brownlow Medallist to play on if he doesn't want to. But, as he had previously said during the week, Matthews regards Voss' status as a contracted player as reason enough to plan for a 2007 Lions outfit that includes the 289-gamer.
"You are asking the wrong person," Matthews said when asked of Voss' intentions.
"He's contracted and we expect him to play on - but if he decides not to, that is his call. I've clearly said he's still valuable to be playing next year. But you can't actually handcuff him to the centre square!"
With Nigel Lappin, Richard Hadley, Jonathan Brown and Jamie Charman all expected to return from serious injuries in time for the start of next season and osteitis pubis victim Chris Johnson likely to benefit from an uninterrupted pre-season, Matthews thinks the Lions can go into 2007 with confidence.
"We start this pre-season much better than we started last pre-season. The old best case scenario - half the team that played tonight won't be there in round one, they'll be replaced by a better half," he said.
"We're really playing half a team that started the year between numbers 30 and 45 on our list. Some of those might have elevated themselves much higher but once we had a few injuries, the players we were playing were basically rookies - elevated rookies.
"We've played games where we've had four guys who started the season as rookies - when you do that, you start behind the eight-ball and that puts too much pressure on others.
"But if you look at the list and pick your team now and who might be available round one next year there are more capable players and guys who haven't got a game but who have played a bit."
