Despite winning the first-leg of their Champions League last-16 tie against Porto 5-0, Jurgen Klopp didn’t take too many chances in the return match.

The Reds may have only managed a 0-0 draw but the German manager named a very strong starting line-up to ensure his side progressed safely into the quarter-finals of the tournament.

But Klopp did make a few changes, with the likes of Virgil Van Dijk, Mohamed Salah and Alex Oxlade-Chamberlain all dropping to the bench.

But one man that was named in the starting XI was Roberto Firmino.

The Brazilian has played 38 matches in all competitions this season and is so important to this Liverpool side.

In fact, he’s so important that some Liverpool supporters claim that the forward isn’t part of the system, he IS the system.

Firmino’s work-rate from the front sets the tone for the whole squad to carry out Klopp’s ‘gegenpressing’ tactics at the club.

And it’s only this season - his third in England - that everyone has started noticing just how important he is. Not only has he defended from the front, he’s also notched 22 goals in all competitions.

It’s safe to say he’s proved plenty of people wrong.

One of those people he’s proved wrong is former Liverpool striker Peter Crouch.

Whilst writing a column for the Daily Mail, Crouch has admitted his first impressions of Firmino couldn’t have been more wrong.

CROUCH REVEALS HIS FIRST THOUGHTS ON FIRMINO

"How wrong can you be? Watching Roberto Firmino charge around against Porto on Tuesday night, I thought back to the initial opinion that I formed when he arrived in England,” Crouch wrote.

"Firmino, at the beginning of the 2015-16 season, looked to be a player with a nice touch and a fair bit of skill. But I felt Liverpool had signed someone from Hoffenheim who would end up getting no more than 10 goals and would turn out to be a typical ‘galactico’ player.

"Look at Firmino. He is a top goalscorer, but the thing that blows me away is what happens when he loses the ball. Straight away he’s on his feet and gets it back. He must be an absolute nightmare for defenders to handle."

Crouch is spot on.

Firmino has earned plenty of plaudits after improving his end product this season but when you combine that with his incredible work-rate, you get a very good player.

While Crouch may not have been aware of Firmino’s talents when he first arrived at Liverpool, Klopp knew just how good he was when he was appointed manager back in October 2015.

KLOPP'S REACTION WHEN FIRMINO SIGNED FOR LIVERPOOL

The Liverpool boss has previously revealed his reaction when he realised Firmino had signed for the Merseysiders.

"He was a player I thought was one of the best in the Bundesliga so, when I saw that Liverpool had signed him, I thought: 'How could Liverpool do this?" Klopp admitted.

"They were not in their 100 per cent best moment and other clubs would have spent more on him so I thought immediately: 'What a good transfer for them.' I thought they had made a good signing because I felt pretty sure clubs would have paid a lot more for him."