Rangers are set to clash with rivals Celtic in the first big cup final of the season on Sunday at Hampden Park.
The Glasgow giants have not lost a game since Michael Beale took charge of the club last year and have won all of their games barring one, the last Old Firm derby against Celtic.
Beale has a few injury issues to sort out and Lundstram is a major doubt ahead of the cup final on Sunday.
Malik Tillman is also nursing a hamstring problem but Hartson believes Lundstram’s absence could be as big a miss for Rangers.
He believes that the defensive stability and composure that the midfielder provides would be essential for Rangers against a very attacking Celtic midfield.
The former Bhoy pointed out that Lundstram was a big player when Rangers beat Celtic in the Scottish Cup semi-final last season.
Hartson said on the Go Radio Football Show: “Tillman is a very good player, [but] I’d be looking at Lundstram as a big miss.
“He is somebody that gives composure in the middle of the park, he has got good vision, he gives you that bit of stability, he protects the back four and when you look at Celtic’s midfield – [Reo] Hatate drives forward, [Callum] McGregor and [Aaron] Mooy – you need somebody to cope with that.
“What Celtic can do in the middle of the park, they are free-flowing and get forward, they can get wide, they can get into the box.
“So, I would be looking at Lundstram as big a loss.
“When Celtic lost to Rangers last season in the semi-final, John Lundstram hit the post during the game, he got box to box and he was pivotal in Rangers winning that semi-final.
“Yes, I get his [Tillman] ability and his influence in the game if he is fit but if Lundstram is out, it would be another big loss for Rangers.”
The 29-year-old midfielder was not part of the squad when Rangers beat Livingston last weekend.
