Danny Röhl was left counting the cost of the international break as he revealed three first-team regulars at Rangers could be out for the rest of the year.
John Souttar was injured in the warm-up of Scotland's World Cup qualifier against Denmark at Hampden Park on Tuesday night and missed the 4-2 win which qualified Steve Clarke's side for next summer's tournament in North America.
Fellow centre-back Derek Cornelius, on loan from Marseille, had to come off in the first half of Canada's game against Venezuela after missing the previous game against Ecuador due to a muscle injury, while Tottenham loanee Mikey Moore, 18, also picked up a knock playing for England U19s.
Youngster Bailey Rice, who has not been part of Röhl's first-team plans, will require surgery while Portugal U21 striker Youssef Chermiti and Scotland back-up goalkeeper Liam Kelly also sustained injuries.
Ahead of Saturday's Scottish Premiership game against Livingston at Ibrox, where out-of-favour defenders Clinton Nsiala and Emmanuel Fernandez will come into contention, the former Sheffield Wednesday boss considered his injury list and said: "It's not so easy. Today I need a list because we have a lot of problems.
"I think at first I'm very happy, very proud of my players, what they achieved. I think this is outstanding. It's always fantastic to see this [on international duty].
"But then on the other side, before the international break we had nearly no injuries.
"And now we have John [Souttar] out with a muscle injury. We have to wait [to see] how long.
"Mikey [Moore] is out with a muscle injury. We have to wait to see how long. It's difficult to say at the moment.
"Derek [Cornelius] has to go to a specialist with a muscle injury. Could be a serious one, a big one.
"Bailey [Rice] got an injury last week in training, a muscle injury and will be out for longer.
"Youssef [Chermiti] is a big question mark, he got a kick. Liam [Kelly] is a big question mark.
"Kieran [Dowell], Dujon [Sterling] and Rabbi [Matondo] made a huge step in the training process, but they need minimum one more bigger game before they are really part of the squad. And Findlay [Curtis] is back after a small injury."
Asked to clarify the severity of the injuries in his squad, the former Germany assistant coach replied: "John and Mikey, I hope at the end of December. But it's a muscle injury, it could be 25 days, it could be 40 days. You never know.
"Derek at the moment, I have a little doubt that it's just four weeks, five weeks. It could be longer.
"Yeah and Bailey, today [Friday] is Bailey's surgery, it's a big one.
"This is football and it happens. I know this because I worked for both sides. For the national team, it's important to have the players.
"It's always an honour to play for your own country. As a club manager, you always want to protect your players, that's what it is, football happens.
"I had some good conversations the last couple of days with some other players. I think it's now also an opportunity to step up.
"It's about solutions and hopefully we have more good solutions."