The former Liverpool defender is a big fan of the Scotland captain and has backed is former side to reach the Champions League final once again
Former Liverpool star John Arne Riise has identified Andy Robertson as one of the top left-sided defenders in the game and insists he is the "perfect" modern full-back.
Riise won a Champions League title with the Reds during his seven-year spell with the club, with Robertson now hoping to do the same as Liverpool look forward to their quarter-final second-leg clash with Porto.
Jurgen Klopp's side are 2-0 up from the first meeting, a game that Robertson had to sit out due to suspension, but as he prepares to feature in Portugal, Riise believes the Scot is up there as one of the world's top left-backs.
When asked his opinion on who can be considered the best in that position, Riise told Goal. "To be honest, the way football is played now Andy Robertson is up there because of his energy and his way of going forward.
"Robertson is more [an example of] today’s modern football full-back. You need to be able to run up and down, make crosses, make assists, shoot, and also be good defensively. He’s like the perfect modern left-back. I’m a big fan.
"I was probably one of the first who started the modern full-back thing, being very offensive, up and down all the time, making passes, shooting, scoring goals. It was quite new when I started doing it. Now, every full-back has to be able to go up and down, and I love that style of play."
And what does Riise like the most about Robertson's game?
"His energy. He never stops," the Norwegian added. "He rarely has a bad game, and he always gives 100 per cent. The way he runs forward brings excitement."
As much of a fan as Riise is of Robertson's game, he does see room for improvement for the 25-year-old Scotland captain and believes he needs to add goals to his game.
"The only thing with Robertson is I want him to be more of a goal-scoring threat," Riise said. "Score more goals, that’s the only thing I want. He has everything else."
With Liverpool looking to go one step further than last season in the Champions League, where they were beaten finalists, Riise is sure they're capable of at least getting to the final again.
"The Champions League is difficult to win because those two games can change everything," he added. "What I saw against Bayern, especially away from home, was unbelievable. So they’re good enough to go back to the final."
The 38-year-old also believes he would have thrived playing under Klopp but says he is will always be grateful to Rafael Benitez for guiding the Reds to the Champions League on that famous night in Istanbul in 2005.
"I’ve thought so many times over the last few years what it would be like to play under Mr. Klopp, because his style of play would have suited my game," Riise said.
"I was lucky to play for some great managers. Obviously Benitez because he gave me the chance to win the Champions League, but I also loved playing for [Claudio] Ranieri when I was at Roma.
"It’s hard [picking a favourite] because I loved all my managers. Mainly because I always played!"