Ally McCoist says it will be "very, very difficult" for Celtic and Rangers to turn down offers for their star strikers.
Alfredo Morelos has been linked with several clubs and Ligue 1 side Lille were last month reported to have discussed personal terms with him.
Edouard, who scored a hat-trick in Celtic's 5-1 win over Hamilton Accies on Sunday, has been mentioned in connection with the likes of Manchester United, Leicester and Tottenham Hotspur.
Speaking on talkSPORT, Ibrox legend McCoist said business will be a priority for Celtic and Rangers when it comes to their key assets.
Asked if selling Morelos would benefit Rangers in the long run, McCoist replied: "Absolutely. I don't think there's any doubt about that.
"I'm Morelos' biggest fan and I was up at Aberdeen watching the game at the weekend.
For more Celtic news join our new group Celtic Live - News, transfer rumours and chat from Celtic Park
"He was OK, he did fine. He didn't look to me as though he's firing on all cylinders.
"I think, particularly now, and I include Celtic in this, if an offer comes in for Edouard or Morelos, it's very, very difficult for those clubs to knock it back.
"Because there's no doubt about it, they have slipped behind in the financial race, particularly with teams down south.
"Survival is of paramount importance. I understand the importance of the season for everybody up here but, at the same time, business will overrule the lot.
"Edouard was fantastic yesterday, he got a hat-trick. Morelos is key to Rangers moving forward this season.
"But the most important thing is, if you do sell him, that A - you get a good price and B - you have to replace his goals.
"I've said for a long, long time - and I know as a manager sometimes you have to show strength - but we spoke about it last week.
"We talked about somebody like Alexis Sanchez coming back into a dressing room at Manchester United, you don't want somebody who doesn't want to be there.
"It's not a good vibe for the rest of the playing staff, you need everybody singing from the same hymn sheet.
"In that respect, I don't think that would've been a good move.
"I think Morelos will move if the offer is acceptable to Rangers."
Morelos started at Pittodrie as Rangers beat Aberdeen 1-0 in their season opener.
.png?w=600)
