Liverpool fringe players like Marko Grujic, Divock Origi must prove worth
With some of Liverpool's star names ready to return to action over the next week, competition for places is about increase to such a level that many of those who lined up in Wednesday night's 4-0 preseason stroll at Tranmere will soon not even be able to make a 22-man squad. And that's without taking any potential new signings into account.
Youngsters Ryan Kent, Pedro Chirivella and Sheyi Ojo all caught the eye at Prenton Park and will be looking to build on that in Friday night's game at Wigan Athletic because once the senior players return, they may not get another chance.
Klopp will already have a clear idea of who his preferred option is at each position, but the battle for the back up places will be intense over the next few weeks. Training sessions will have much more influence on Klopp's thinking than the friendlies, but there will be some interesting positional battles as players look to secure a place in the squad for the upcoming season.
Supporters obviously aren't privy to what happens in training, so the games are their only opportunity to assess how the battle for places is progressing. Every selection made by Klopp will often be scrutinised, as fans look for clues as to what the pecking order is for each position. For example, Trent Alexander-Arnold started at Tranmere ahead of Nathaniel Clyne, who replaced him for the second half. There was almost certainly no significance in that decision but it didn't stop some fans from pondering whether it meant that Clyne was being put on notice. Alexander-Arnold may well pose a genuine challenge this season, but it's unlikely to happen at the start. The youngster has made rapid progress over the past 12 months while Clyne stagnated a little towards the end last season. Clyne should start the season as first choice but he knows the local youngster is an ascending talent who will be pushing for a place sooner rather than later.
Another interesting battle is for the number two goalkeeper spot. It would be a big surprise if Simon Mignolet didn't retain his starting spot after the impressive way he ended last season, but his understudy's identity is less clear-cut. Performances in training will be the determining factor in whether Loris Karius or Danny Ward wins the job, as there are just too many variables in friendly games themselves to be able to judge goalkeepers fairly. Karius was virtually a spectator against Tranmere and therefore had no chance to impress anybody. Whoever plays on Friday at Wigan may find themselves in a similar situation.
Friendly games against lesser sides are tough on keepers as it's almost a no-win situation. Mistakes in these games might see a player fall down the pecking order but impressive displays probably won't see them rise up.
Just ask Marko Grujic. The young Serbia midfielder was the star of Liverpool's summer friendlies a year ago but it counted for nothing when the real thing kicked off, as he found his opportunities in the first team severely restricted and then missed a large chunk of the season through injury. His first year at Anfield was largely a write off through no real fault of his own.
This is a big year for him and he kicked off his preseason in style with a goal and an assured display against Tranmere. Regardless of how well he plays over the coming weeks, though, there is a good chance he'll still find himself even further away from a first team place than he was a year ago.
Grujic was already behind Adam Lallana, Emre Can and Gini Wijnaldum but now Klopp has earmarked Philippe Coutinho for a deeper role this season, pushing Grujic further down the queue. Should Liverpool's pursuit of Naby Keita prove successful, the youngster's task might start to look almost impossible, even accounting for Liverpool's extra fixtures this season.
It's a similar situation up front, where Liverpool have a number of established senior players fighting for places and the arrival of Dominic Solanke has given Divock Origi a real problem. Those two now appear to be going head to head for the right to be the number three striker this year.
Roberto Firmino is Klopp's number one striker, with Daniel Sturridge a top-class alternative when fit and available. Origi would appear to be next in line but Solanke hasn't joined Liverpool to sit on the bench and despite initial reports that he'd begin the season in the Under-23 squad, there is a growing feeling that the former Chelsea youngster may well usurp Origi unless the Belgium international significantly ups his game.
If he plays at his spring 2016 levels, Origi should have little to worry about, and might even be pushing Firmino and Sturridge all the way for a spot in the team. The Origi we saw for most of last season, however, will quickly find himself behind Solanke and also perhaps Danny Ings.
Of all the players in need of proving themselves this summer, Origi might just be top of the list.
Dave Usher is one of ESPN FC's Liverpool bloggers. Follow him on Twitter: @theliverpoolway.