Ashman made a splash in the recent Autumn Nations Series when he came off the bench against Australia and scored a stunning debut try in the 15-13 win at Murrayfield.
The player has struggled for game-time at Sale and the loan move to Glasgow was designed to give him more minutes alongside a number of his Scotland team-mates and help out the Warriors who had lost their co-captain Fraser Brown to a knee issue.
However, injury problems at Sharks have scuppered the deal.
Sale don’t have a game this weekend but have decided they need Ashman. They initially recalled him for last week’s match against Saracens but now the loan has officially ended.
“Part of the detail of the agreement was that if they had a couple of injuries in that position they could call him back and they had a couple of injuries pretty much straight away,” explained Wilson, whose side host the Dragons on Saturday in the United Rugby Championship.
“He was always their player so there was always the risk of him going back but I didn’t think it would be before he’d even started so it’s a bit disappointing, a bit frustrating but at the same time understandable – he’s their player, not ours.
“Ewan Ashman would have been a good one and we’ll see how that progresses because the relationship between the clubs is still there.”
The better news for Glasgow is that Brown’s knee injury is not as bad as first feared and they also have three fit hookers in George Turner, Johnny Matthews and Grant Stewart.
Turner will start against Dragons at Scotstoun, with Matthews on the bench, as Glasgow look to bounce back from last weekend’s last-gasp loss to Benetton which still rankles with Wilson who has made five changes.
“We were in a position to win – albeit win ugly – with 90 seconds to go and in possession of the ball inside their 22. You’ve got to be able to close those games out,” said the coach.
Internationals Sam Johnson, Rufus McLean, George Horne, Jamie Bhatti and Matt Fagerson all drop out, with one eye on next week’s European opener against La Rochelle.
There is a debut for New Zealand full-back Josh McKay in a reshuffled backline which sees Cole Forbes moved to the wing, Kyle Steyn switched to outside centre and Sione Tuipulotu at 12. Sebastian Cancelliere comes in on the other wing and Ali Price returns at scrum-half.
In the pack, Zander Fagerson is back at tighthead, with Oli Kebble switching to loosehead and co-captain Ryan Wilson also returning.
Wilson is looking forward to seeing McKay in action.
“He’s a sharp attacking threat,” said the coach. “Playing at home on a fast track in your first match will hopefully suit him.”
There will be a minute’s applause before the game in memory of Siobhan Cattigan, the Scotland internationalist whose death at the age of 26 was announced this week.
“Everyone at Glasgow Warriors would like to send a message of condolence to Siobhan’s family and friends,” said Wilson. “It was very sad news.”