Garner is impressing on-loan at the City Ground.
Speaking to The Sun via Freebets.com about the youngster, the 32-year-old said: "He's an absolute baller. What a player! And he's only 20.
"You watch him play with such maturity, he reminds me of Xabi Alonso with the maturity he's got.
"A lot of people don't realise how hard it is to play football simply.
"This guy makes everything simple and look so easy. He's hard in the tackle, he's not scared, his long-range passing, his short range passing is amazing.
"I've seen him score goals with both feet, what can he not do? I'd not be surprised if United tried recalling him, but that would a huge mistake for Garner if he did.
"He needs to stay at Forest and develop. He's enjoying his football.
"But in 18 months, don't be surprised to see him playing in the England squad - he's that good. Gareth Southgate will be paying attention."