Having beaten Porto 5-0 away in their Champions League tie, Liverpool were virtually assured of a quarter-final spot heading into Tuesday’s home leg.

Here are three things learned from the match, as the Reds duly gave a controlled performance, drawing 0-0 to progress to the last eight.

LIVERPOOL HAVE DEPTH TO MAKE DEEP RUN

The team selected on the night didn’t tear Porto apart like Liverpool’s regular XI did in the first leg – for which much credit must be given to Porto’s own improvement – but they acquitted themselves well, showing the Reds’ squad has a depth they haven’t been given credit for.

Across the back line and midfield, players pressed their claims for starting berths. Where Liverpool’s strength on the bench truly stood out was in midfield, as Jordan Henderson delivered one of his better performances this season and the good Emre Can turned up. In those two, James Milner, Georginio Wijnaldum, Adam Lallana, and Alex Oxlade-Chamberlain, Jurgen Klopp has six players for three midfield spots – a welcome headache.

That depth will be crucial as Liverpool continue to fight on two fronts this season.

Henderson was calm and composed in midfield.

KLOPP LEARNS GAME MANAGEMENT

Jurgen Klopp has been criticised for having only one approach to football. But while Tuesday’s game didn’t exactly showcase a clear-cut Plan B, it did show that Liverpool at least have a Plan A lite, where they rein in their pressing and manage a game rather than going all-out.

The heavy metal football is exhilarating, but it can come back to haunt Liverpool at times. Just think back to the famous 4-3 win over Manchester City in January, where they took a 4-1 lead but spent the final few minutes of the game holding on for dear life.

On Tuesday, with the tie having been sewn up in the first leg, Liverpool showed they know how to play with their foot off the gas. That’s not exciting, but it’s what wins trophies.

Klopp showed he knows Liverpool don’t have to go all-out every game.

CASILLAS GOES OUT ON A HIGH

Iker Casillas is having a sad end to a glorious career. Once among the best goalkeepers in the world, the Spaniard has had to endure a heartbreaking split from Real Madrid, ushered out the back door on his way to Porto, and then losing the number one spot at the Portuguese club.

With this game rather inconsequential, Sergio Conecao decided to give his veteran keeper one last hurrah. Casillas, who holds the record for Champions League appearances, with this his 171st, is leaving Porto at the end of the season, and this likely was the 36-year-old’s final appearance in the competition.

In which case, it was fitting that he ended with a clean sheet – a record 58th in the competition – and Casillas earned it, pulling off a stunning late save to deny Danny Ings.

Casillas ended his Champions League career with a well-earned clean sheet.