The Scot has developed into one of the finest left-backs in the world and a leading figure within Jürgen Klopp's squad following his arrival from Hull City in the summer of 2017.
While playing golf with Adam Lallana during the recent Pro-Am at Valderrama ahead of the Andalucia Masters, Milner saluted the all-round contribution from Robertson.
"I think how good Robbo has been since he's been at the club has been incredible really," the vice-captain told the European Tour's website.
"The fans love him. I think it started with that 90-yard press of Man City – he pressed everyone in their team I think, went to the 'keeper and then did them all again!
"He's got great quality and [is a] good defender. He's good around the dressing room as well, he's good craic.
"That's the one thing we've got as a team, we've got a great team spirit. You need lads like Robbo.
"As good as he is on the field, he's brilliant in the dressing room as well."