The midfielder picked up a knee problem against Celtic on Wednesday and has been ruled out of Sunday's friendly against Lazio.
Christian Ziege was also injured against Celtic, misses Lazio and the pair have been handed 'an outside chance' by the boss of being fit for our Premiership opener at Everton next Saturday.
Gus Poyet faces another 10 weeks out with a knee injury and Ledley King, Steffen Freund and Steve Clemence have yet to take any part in pre-season friendlies.
Anthony Gardner has only played a half and has just recovered from a viral infection while Les Ferdinand has had the final pin removed from his broken wrist but, although he has trained throughout, needs to strengthen before playing again.
It all adds up to a nightmare scenario for Glenn.
"I've got to say I'm going into the Lazio game with a little trepidation because of the injuries," he admitted after training this afternoon.
"We've lost Christian Ziege, probably for the start of the season, which is a big blow.
"He's got an outside chance for Everton and it's the same with Darren Anderton with a knee problem that he played on with against Celtic. Those two are definitely ruled out this weekend.
"Les has had his pin out and is training relatively well without playing a full-scale match. It's been a bit frustrating for him but he's kept himself in shape.
"Now he's got the final pin out he has to strengthen the wrist and we might look to get a practice match out of him next week.
"Ledley won't be ready for Everton. If everything goes well he won't be ready for another three weeks.
"Steve Clemence hasn't kicked a ball yet, Steffen Freund is due to come back next week and we'll assess him but he'll take some time and will need reserve matches.
"Anthony Gardner's infection has cleared up and he'll be in the squad if we get clearance from the specialist by the weekend.
"I'm looking at the squad and one thing is for sure - we can't pick up another injury.
"It's a horrendous way to go into the season, it really is. We've a list as long as your arm -of players injured and key players as well.
"It's very frustrating for me because when you kick off, no-one takes that into consideration. You are on offer from the first day in the Premiership. But we've had to deal with it before and we'll continue to do so."
Injuries continue to frustrate Glenn Hoddle's pre-season plans - Darren Anderton is the latest player to join the list.