Erik ten Hag has had quite the impact on Manchester United since he was appointed as the club's manager in May as the Red Devils chase a coveted Champions League spot.
The 52-year-old got off to a disastrous start during his time at United as they lost their first two Premier League matches and sat bottom of the table, having conceded six times in the process. However, the Red Devils have gone from strength to strength since Ten Hag gave his squad a brutal punishment after the 4-0 defeat at Brentford.
Ten Hag made his entire team do a brutal 13.9km run the day after the clash at the Brentford Community Stadium, but it was something that worked. The Red Devils have won 10 of their last 14 league matches and are in an ideal position to challenge for a top-four place following their 1-0 win over Wolves on Saturday afternoon.
But the Dutchman has had to make some more ruthless decisions on the way, including the way he handed the Cristiano Ronaldo situation. So, with that in mind, here are five rules Ten Hag has set to his players and how he has implemented them.
Rashford lateness
Ten Hag reportedly warned his players before the season started that they would be dropped if they were late for training or team meetings as he set his rules from the get-go. This was despite how well a player was performing and their importance to the team as he tried to change the ethos and culture at Old Trafford.
And the former Ajax boss perfectly demonstrated his power in the changing room as he dropped an in-form Marcus Rashford for the trip to Wolves, despite scoring in his last two matches. The 25-year-old overslept and was late to a team meeting prior to the Red Devils' clash at Molineux on December 31, and was therefore dropped to the bench.
Ten Hag's U23s demand
Having demanded the change the way United play from the academy upwards, Ten Hag took charge of the reserve team last week in a bid to open up a better pathway into his senior side. The Dutchman revealed how he told Old Trafford bosses during negotiations last spring that he would only agree to become their new boss if he was also given full control of the club's Under-23 squad, and he got that chance in the festive period.
Ten Hag works closely with official Under-23 boss Mark Dempsey and coach Paul McShane - but takes the ultimate decisions on all team selection matters and even determines players' positions and how many minutes they are given on the pitch. He undertook a similar dual role at Ajax because he believes it is the best way to get an accurate overview of the talent coming through the system. This is something United never used to do before he came in.
Ronaldo punishment
There were many question marks raised about Ronaldo's future ever since Ten Hag was appointed given his style of football and the forward's unwillingness to press from the foot. Ten Hag's teams in the past have pride themselves on pressing and working hard in and out of possession - something Ronaldo doesn't do - and the relationship between the pair turned toxic very quickly.
Ronaldo was punished on several occasions for a variety of issues, including leaving Old Trafford early before the end of two matches and also refusing to come on as a substitute against Tottenham. Ten Hag handled the latter excellently and decided to not include Ronaldo in the matchday squad at all for the trip to Chelsea after breaching rules and recalled him straight away for their following game in the Europa League.
But the final nail was put in the coffin when Ronaldo decided to speak out negatively about the club, the Glazers and Ten Hag, where he claimed he doesn't respect his manager. This was another breach of his contract and United ended his terminating his deal by mutual consent, and there's little doubt Ten Hag also had a say on the decision.
Personal chefs banned
Right at the start of Ten Hag's reign, the Dutch boss banned personal chefs from cooking the players' meals on matchday and throughout the week. The players have to eat exactly what is prepared by the club, so that Ten Hag can easily monitor their diet and how they are functioning on a daily basis.
Each United player has a custom-made diet plan drawn up and will have their Body Mass Index (BMI) checked monthly to make sure they are staying in shape. This is to prevent weight issues and problems with staying fit to ensure his squad are in the best possible condition every week.
Complain to Ten Hag
Despite his tough stance on so many issues, Ten Hag also told his players to come and see him if they have any problems, rather than going to their agents. The Dutchman wants to develop a strong bond with United's players, believing reciprocal trust and respect is one of the key factors behind any successful team.
Last season, United had lots of issues with players going to see their agents first and leaking stories out to the press, which causes lots of problems. Gary Neville said last February: "What they do not realise is that unfortunately, when they go to the media then those media people go to us - so we know who is briefing.
"The reality is that we do not like it, but we know who it is. We are not going to throw people under a bus here because we have that journalistic respect."