Liverpool's 5-0 first-leg lead proves insurmountable in 0-0 draw vs. Porto

LIVERPOOL, England -- Three quick thoughts on Liverpool's 0-0 Champions League draw with Porto at Anfield on Tuesday, which sees the Reds move on to the Champions League quarterfinals 5-0 on aggregate.

1. Liverpool's first-leg win put comeback out of Porto's reach

On an entirely forgettable night, Liverpool reached reached the quarterfinals of the Champions League, ending their nine-year absence from that stage of the competition.

Holding a 5-0 advantage from the first leg, this return fixture was a procession from the first second, and there were no concerns of an improbable response from Porto, with Liverpool coming closest to scoring when Sadio Mane hit the post in the first half and substitute Danny Ings had a header saved by Iker Casillas.

The reward for Liverpool's performance in Portugal last month was for the second leg to have preseason-like feel at this stage of the season. And the biggest boost resulting from it is that it appeared to be injury-free prior to the weekend's game at Manchester United.

To say the odds were against Porto was an understatement. To get to the quarterfinals, Sergio Conceicao's side were required to pull off one of football's greatest ever comeback stories, while breaking a number of long-standing records in the process.

Klopp had a call to make with his team selection: either put out his strongest XI in the hope of maintaining rhythm or to rest players ahead of Saturday's trip to Old Trafford. In the end, he settled for a blend of the two options, making five changes, while starting Mohamed Salah and Virgil van Dijk on the bench.

Having probably made travel arrangements and bought tickets for this game well before the first leg, Porto's travelling support made the most of their trip to Merseyside, even if their team's performance didn't come close to the same intensity.

Salah eventually appeared in the 73rd minute, but by that stage his two forward partners, Mane and Roberto Firmino, were off the pitch and beginning their recovery for the United game. Liverpool's job was done long before these 90 minutes.

2. Lallana's road back blocked by Milner

Liverpool's midfield has been forced to evolve in wake of Adam Lallana's long-term absence this season. No longer is the energetic, high-pressing style that Klopp wants so dependent on Lallana being in the side.

Klopp had admitted the club mismanaged the 29-year-old's return from long-term injury, rushing him back too soon. Therefore, Lallana has failed to generate any sort of rhythm in his 11 appearances in 2017-18. His 90-minute outing against Porto was much needed, but he didn't go on to pull up any trees during it.

In truth, Lallana's task on Tuesday wasn't the easiest. He replaced the 32-goal Salah in Liverpool's front three. An instant return to midfield, where he thrived last season, will be difficult.

James Milner continued his rich vein of form in central midfield against Porto, with his willingness, experience and versatility making him one of Liverpool's best players in recent games.

Somewhat surprisingly, Milner, 32, has the most assists in this season's Champions League with seven, and was continually looking to add to that tally with a number of pin-point accurate long passes. He should have had assist No. 8 for the through ball that led to Mane striking the woodwork in the 31st minute.

Lallana's loss has been Milner's gain. No longer shifted out as an auxiliary left-back, Milner is now taking centre stage.

3. Liverpool's vast growth since Porto's last visit

Football is an incredibly fast-moving business. Days feel like weeks and weeks become months. A year can appear to take the form of a decade. Liverpool as a club are virtually unrecognisable from when Porto last visited it -- back in November 2007.

When the Portuguese side last played at Anfield more than 10 ago, Liverpool were in the midst of a civil war. Due to displeasure at the ownership of George Gillett and Tom Hicks, nearly 2,000 Liverpool supporters marched towards Anfield in support of then-manager Rafael Benitez.

It's much simpler these days. "Win the European Cup for me," read a banner in the Kop on Tuesday.

While not perfect, Liverpool are relatively settled on and off the pitch these days. It feels like it's all beginning to click under Klopp's management. The club's first appearance in the quarterfinals of the Champions League since 2009 could be out-done by a runners-up finish in the Premier League this season, but Liverpool fans are starting to believe their European adventure won't end in the last eight.

Given other rivals' struggles and Liverpool continually solidifying their place in the top four, Klopp may well be able to concentrate more on the Champions League in the closing weeks of the season.

Liverpool are gathering serious momentum at the business end of the campaign. It's an entirely different story to last term when they limped over the line in fourth. Things are continually changing at Anfield -- positively these days.