Milner is Liverpool's pre-season king, and only one man ever came close to beating him

However, few can match James Milner when it comes to setting the bar as high as possible.

Regarded as football's pre-season king, Milner is someone who has been at the top of the game for longer than most, and it doesn't take a genius to work out why.

The Liverpool star is enduring his 21st pre-season campaign this year as he looks to get ready for another demanding season under Jurgen Klopp.

Some footballers dread the customary hill runs, bleep tests and gym work that come with getting ready for a long, hard season, however the 36-year-old continues to put them to shame with his superhuman displays.

Football is a much more scientific business than it was when Milner made his professional debut with Leeds in 2002, after all, pre-season in those days sometimes still consisted of pints and days on the golf course.

While it may have been easy for a fresh-faced Milner to shine in those days, it's been much more difficult in recent years.

But, as Stuart Pearce told talkSPORT, it's the player's professionalism in moments like this that have kept him at the top of the game.

"I didn't think James Milner would get [England] senior caps when he was working with myself at the Under-21 level," said Pearce.

"He's a brilliant lad and brilliant professional. He has maximised his potential and has 40-odd caps.

"Players like that have got my utter respect, especially guys like Milner and Harry Kane. They have maximised every ounce they have got band are the ultimate professionals."

Klopp's appointment as Liverpool boss in 2015 saw a culture shift at Anfield with an added focus on becoming the fittest side in the Premier League.

But even among his younger teammates, Milner was able to prove himself as the fittest player in one of the Premier League's fittest teams, with just one former Red, Kevin Stewart, able to get anywhere near challenging him.

Speaking to Goal in 2020, Trent Alexander-Arnold said: "We are a fit team, there are a lot of players who have great engines - Hendo, Gini, Robbo.

"But Milly, I don't think I'll ever see anyone as fit as him.

"I remember a few years ago Kev Stewart would give him a run for his money in pre-season.

"But, considering his age and how long he's played for, to still be the fittest player in arguably the fittest team in the world, and by some margin, that takes some doing."

Any normal footballer would see their stamina levels rapidly decline in their mid-thirties, but not Milner.

Football clubs tend to keep scientific performance statistic to themselves, but last summer Milner shared a sneak peak of his running times.

In the session in question, the midfielder ran 8.5km in just 34 minutes, a performance that he has every right to brag about on social media.

Averaging less than four minutes per kilometer, it was no surprise to see Milner retain his status as a key player under Klopp.

Those pre-season preparations clearly stood the 36-year-old in good stead as he made 39 appearances for the Reds in all competitions as Liverpool won both the Carabao Cup and FA Cup, while finishing as runner up in the Premier League and Champions League.

While his contract did expire at the end of last term, Milner's astonishing fitness levels - along with his obvious on-field talent and leadership in the dressing room - were enough to convince Klopp to offer him a new one-year deal, with the head coach admitting that releasing the player simply wasn't an option.

Upon signing the contract, Klopp explained: "He continues to perform to a level that meant we simply couldn't afford to lose him.

"His professionalism is the benchmark for any athlete and it's why he sets the tone for this team with his ability and attitude.

"We had the longest campaign possible last season and Millie only got stronger and better and more influential as it went on."

Milner could be forgiven for letting his levels drop as he competes with Liverpool's next generation of young stars such as Fabio Carvalho, Kaide Gordon, Harvey Elliott and Curtis Jones in the coming months.

That said, with the model professional still topping the fitness charts in the Premier League, it would be no surprise to see Milner playing at the highest level into his 40s.

Doing so would be incredible but, given the astonishing heights the midfielder has reached in his career, it would be foolish to predict when Milner might convince us that he is, in fact, human.