Victories at Tranmere and Bradford were followed by four winless matches against Borussia Dortmund, Sevilla and Sporting Lisbon in the United States and Napoli in Edinburgh.

Jurgen Klopp's side ended their warm-ups with a 3-1 comeback win over Lyon in Geneva.

Champions Manchester City had a less hectic schedule, with games against West Ham (won 4-1) and Wolves (lost on penalties) in China, Kitchee (won 6-1) in Hong Kong and Yokohama F Marinos (won 3-1) in Japan.

The Reds, who are bidding to win the English title for the first time since 1990, are now playing in six competitions this season, after losing Sunday's Community Shield in a penalty shootout against Manchester City.

But does a bad pre-season matter?

The case to say it does matter

Only three teams in the past 20 seasons have lost more than half their pre-season friendlies - not counting the Community Shield as a friendly - and gone on to win the Premier League title.

Manchester City only won one of their three pre-season games last season, and in 2013-14 they had a similar record to Liverpool this summer with three wins from seven.

The other team to fall below the 50% win mark is Arsenal who, in their Invincibles year of 2003-04, won four out of nine. The Gunners, however, drew four matches that summer.

So if you convert friendly results into points, then Liverpool's 1.4 per game (they drew against Sporting) is only below City's one point per game in 2018 and 1.28 in 2013 this millennium.

Another indicator to say a bad pre-season may hint at a bad season is by looking at previous underwhelming seasons for big clubs.

Manchester United won two of their seven games in David Moyes' only pre-season (2013-14), with Chelsea failing to win any of their four the season they finished 10th (2015-16).

The case to say it does not matter

Roberto Firmino (second from left) scored against Lyon despite only playing 30 minutes of pre-season after winning the Copa America with Brazil

There is a huge caveat when comparing Liverpool's pre-season results to those of previous champions - summer warm-ups were a very different animal until a few years ago.

Before the invention of organised friendly tournaments like the International Champions Cup - which can read like Champions League line-ups - clubs often played English lower-league teams and possibly some local sides in Asia or the US.

For example, in 2014-15 Chelsea's toughest games were arguably 45-minute matches against Fenerbahce and Besiktas on the same day.

Four out of five of City's games in 2011-12 were against MLS sides or a League of Ireland XI.

And Leicester's only matches in the summer of 2015 were against Lincoln, Mansfield, Burton, Rotherham and Birmingham City.

Another reason for Liverpool fans not to get too concerned is that most of their stars barely featured in pre-season.

Two of their front three - Mohamed Salah and Roberto Firmino - and their goalkeeper Alisson Becker only played in the final game against Lyon after returning from international duty.

The third member of their vaunted forward line, Sadio Mane, did not feature at all after Africa Cup of Nations duty.

The line-ups they fielded in their warm-up games are unlikely to have any factor on who faces Norwich in Friday's Premier League opener - for example 27 different players played at least 15 minutes in the game with Lyon.

So, in conclusion, a struggle in pre-season does not necessarily translate into a struggle all season - but only once the campaign starts we will know for sure.