Alfredo Morelos will not be allowed to leave Rangers unless a club tables "a really big offer" - and it "won't happen late" in the transfer window.
Morelos missed Sunday's 5-0 friendly win over Oxford United through injury.
Rangers manager Steven Gerrard says the 23-year-old Colombian striker will be in the squad to face St Joseph's in Europa League qualifying on Tuesday.
"If he did end up going, he would be impossible to replace with days or weeks to go in the window," he said.
"A million per cent, it won't happen late, that's for sure. So, if someone wants to spend a lot of money on a centre-forward and they want my centre-forward, they will have to come early."
Morelos, capped three times for his country, joined Rangers from Helsinki in 2017 and was the subject of a failed £8m bid from Chinese club Beijing Renhe in January 2018.
But he has since extended his contract until summer 2023 and scored 30 goals in 48 games as the Ibrox side finished runners-up in the Scottish Premiership last season.
"I can't control the speculation, but as a club we haven't got a decision to make because a bid hasn't come of any sort," Gerrard said.
"Does anyone want Alfredo Morelos? I don't know, I can't answer that question, but if they do, they best bring a really, really big offer."
Morelos was not among the 23 players who featured at Ibrox against the English League One side, but he watched from the stands and Gerrard revealed the Colombian had missed out with a minor groin injury but would travel to Gibraltar for Tuesday's Europa League first qualifying round first leg after "he trained really well today on his own".
On-loan Liverpool winger Sheyi Ojo found the net along with Greg Stewart, who signed this summer after leaving Birmingham City, Jermain Defoe, Daniel Candeias and 19-year-old centre-half Lewis Mayo.
Gerrard is still hopeful that Ojo's Anfield team-mate and fellow winger, Ryan Kent, will return after last season's successful loan, although there are no talks ongoing with the Champions League winners.
"The only way we will have a conversation is if Liverpool phone us and tell us he is available for loan," he said. "There will be a few more additions, but it's difficult to say whether it will be one, two or three."
Sheyi Ojo scored for Rangers against Oxford
Gerrard believes victories in pre-season have prepared his side well for the start of the season.
"Tuesday's for real," he said. "It will be a tricky game, it will be a sticky game, it will be hot, the pitch won't be great, there will be a lot of challenges for the players, but the signs are good. We are keeping clean sheets and scoring goals."
Gerrard believes the promise goes beyond Tuesday's tie.
"Even compared to last season, we look to have more pace in the team and more dynamic players and hopefully that will let us go to the next level," he added.
"We had a good team and showed a lot of progress and there were certain games where we played very well, but I think it was the consistency where we fell a little short.
"So the idea this season is to have more strength in depth, more quality in the forward areas so that not only are we a more entertaining team but more ruthless and can win more games on a consistent basis."