Speaking to Football Insider, the former Gers star claimed supporters had “seen the potential” of the 27-year-old star at Sheffield United.
John has started both pre-season matches, against the EFL League Two side Tranmere Rovers and the Premier League giants Arsenal, since joining Steven’s squad.
The hard-working midfielder moved north of the border in Bosman deal after his deal at Sheffield United expired.
Alan admitted he was already impressed by what he had seen from Lundstram in the Gers’ warm-up games.
However, he suggested John could take his game to the next level at Rangers.
He told Football Insider: “You can see what he brings. He’s obviously very calm, he’s played at a higher level.
“I think he’s going to be a steady grower. Game on game he’s going to get better and better. We’ve seen the potential over the last couple of seasons.
“There’s obviously room for improvement as well but I think he’ll get that under Steven Gerrard, be an inspiration, and he’ll flourish in a Rangers shirt.
“He’s a top-quality player, very big and strong which I think you need in the SPFL. I think he’s going to be a very good signing.”
The Croatian has been out for a year with a serious injury and Spezia are hoping that they’ll be able to swoop in to seal a deal for his services upon his recovery.
He played zero minutes throughout the 2020/21 season because of his knee injury and it’ll not be easy to ask to break back into the senior team in the coming weeks or months.
12 months in Serie A playing regular football at the high level could allow the defender to get back in shape and return to form after a long period without first-team football.
The player could then return to Ibrox next year and be ready to attack the Scottish Premiership and win his spot in starting XI, which Nikola is capable of doing considering the manager’s previous praise of his work.