EXCLUSIVE: Jermaine Jenas: LVG should heed Utd warnings - or pay with his job

Manchester United may have beaten Liverpool at the weekend, but that victory only papers over the cracks of deeper problems at Old Trafford. Firstly, that was one of the worst Liverpool sides you'll see for a long time. Secondly, the suggestion that many of United's players are unhappy with Louis van Gaal's rigid coaching methods is a serious problem for the manager. Unless he makes some changes, it will only end one way: with Van Gaal losing his job.

One thing players hate is to feel restricted, and United look like a team playing without freedom. They have signed flair players, but they don't play with flair. Some players are best when they’re instinctive but if you're constantly thinking - especially as a forward – ‘I can't go into that area, I can't go too deep to get the ball, I'm not allowed to do that’, creativity is immediately stifled. I can count on one hand the amount of entertaining performances I've seen from Man Utd since Van Gaal arrived. They have been winning games, but if Van Gaal's formula is making the players unhappy it will come at a cost.

Van Gaal knows it's happening, and he's managed to get rid of a few who he thinks are having a negative influence on the group. But the problem for Van Gaal is that there is only one winner in these types of situations. Ultimately, the players have the most power because they can down tools and say. 'I can't play for a manager like this’.

Andre Villas-Boas at Tottenham was very similar in his methods. In a training session, if I came to receive the ball from a right-back, he would stop the session and say, "No, don't stand there to receive the ball; stand there", and he'd move me five yards. I'd be thinking, ‘I've been playing midfield my whole career and I know where I feel comfortable receiving the ball’. But the minute a manager puts those thoughts into your head, you can go onto the pitch wondering whether you’re stood in the wrong place, rather than just doing it instinctively.

A lot of players find it difficult to play under those restraints. Although many have loved working under Van Gaal, there are probably more that can't deal with it. And when you come to England as a manager, you have to be especially flexible because the English mentality is different.

When Juande Ramos was at Tottenham, I played some of my best football. I really took to his methods and regimes, but I was very much in the minority.

The food he had us on was disgusting. Everything was dry and completely flavourless. If you had pasta, you were not allowed any sauce on it whatsoever. If you wanted flavour you had to create it yourself using very meagre options - like a bit of olive oil, salt or lemon juice. That was it. If you had chicken, again it would be dry and plain.

At half-time they cut out our Lucozade drinks - we weren't allowed those anymore because it wasn't 'natural'. Instead Ramos had a fitness coach, a guy called Marcos, who would concoct his own 'juice'. At half-time he'd give you a little cup of it as you walked into the changing room. It was a cold mixture of potatoes, water and pasta - blended to a pulp. It looked like wallpaper paste - same colour, same consistency - the lot. It was absolutely disgusting.

The players thought it was a joke. Ledley King and I told Ramos this but he'd say, "This is all natural foods, it's good for you - you have to eat it."

Sometimes me and Aaron Lennon would try to sneakily eat a couple of wine gums at the back of the bus, but having a bag of sweets felt like breaking the law. When Ramos appeared we'd hide them behind our backs. I was 25 years old and hiding a bag of sweets.

Eventually Marcos said, "OK, I'll try to do something," and the next time we came in at half-time he gave us the cups and beamed, "You'll like this one". It was basically the same stuff, except he'd put a crushed bourbon biscuit in it to try to make it chocolately. Ridiculous.

Sometime Marcos would do little trials on the training ground. He'd hand you a cup and say, "Taste this". You'd try it and say, “That's horrible, what is it?” It would always be the same – potato, rice, water, maybe a bit of fruit. But the bourbon did make it taste slightly better, I'll give him that.\

Looking back now it's funny, but at the time you could just feel the lads switching off. This is the same danger that Van Gaal faces. Personally, I listened to everything Ramos said and I did it, and I've never felt as fit or been as fit. I thrived mainly due to my genetics. I was slim, naturally fit and I had hardly had any body fat. I was the exact type of player Ramos liked. But for other players it was a complete nightmare.

He had a guy from Spain who would fly in every two weeks to take your Body Mass Index (BMI). This guy would never talk. He’d just put you on a machine, which would make a weird noise and then he'd write something on a bit of paper. You wouldn't know until the following week what it all meant. If you ended up in the “red zone”, you’d have to do laps of the pitch until you lost weight.

It was OK for me, but it was different for naturally heavy players like Paul Robinson or Tom Huddlestone. He was asking Tom to get down to a weight he had never been. I was with Tom at Forest at Under-14 level, and he was exactly the same size as he is now - Ramos wanted him to weigh less than when he was a kid.

All these things built up and eventually we had a team meeting and the players said, “We can't do it anymore. I can't live my life like this.” It was borderline depression.

Man Utd players apparently went three weeks without a day off, and Ramos was very similar. It's not the physical element that players are bothered about; it's the mental switch-off. When you've been travelling around Europe and staying in hotels, you just want to spend time with the family for a day or two. It recharges you, and we never really had that.

I recall a time we battered Besiktas in the Europa League. They had a player sent off after about 25 minutes, but even then we played so well that their fans clapped us off the pitch. We had to stay in Turkey for the night and the next day Ramos organised a training session. We all assumed it would be just for the ones who hadn't played, but he made the starting XI do it as well. We couldn’t believe it. “They went down to 10 men so you didn't have to work. Today we're going to work,” Ramos said. Then he put on a ridiculous running session. We were doing sprints down the pitch, then sit-ups, then two sprints, then more sit-ups – the morning after winning a game. That was when he started to lose the majority of the players - when they started to say, “I don't care how fit you're making me, I'm not happy”. Ramos completely lost the group in the end, and that was how it started.

It was a shame because he was a top coach - I thought he was brilliant - but a little bit of flexibility would have gone a long way in terms of the players standing by him. It will be similar with Van Gaal. He needs to be flexible, because players are very powerful. The minute they are unhappy, they don't play well and they stop winning games, and the first person to go when that happens is the manager.