By Alan Hansen BBC Sport football expert

Mourinho (left) is reported to have fallen out with Abramovich

As a manager who has won back-to-back Premiership titles, Jose Mourinho will not stand for people trying to interfere in the players he buys and sells - and quite rightly so.

The minute you start listening to other people is the minute you are history.

But the apparent breakdown in the relationship between Chelsea boss Mourinho and owner Roman Abramovich would not have happened if the Blues were six points clear at the top of the Premiership.

It is when things start to go wrong that the owner or the chairman suddenly starts trying to pick the team or influence transfer activity.

That seems to the case at Chelsea and even though I said last week that I thought Mourinho would be at Stamford Bridge next season, I am not so sure now.

In a situation involving big egos, it is very difficult to pull things together again once it has become fragmented.

In the end, it will come down to results and we are approaching a blockbuster weekend in the Premiership.

On Saturday, Chelsea travel to Liverpool, with Manchester United heading to Arsenal the following day.

THE BIG FOUR COLLIDE Liverpool v Chelsea Saturday 20 January Anfield Kick-off 1245 GMT Arsenal v Man Utd Sunday 21 January Emirates Stadium Kick-off 1600 GMT

Liverpool have struggled against the 'big three' recently and in five league games, Reds manager Rafael Benitez has not even managed a single point against Chelsea.

Nonetheless, Anfield is a daunting place to visit and recently Chelsea's defence has been as bad as it has ever been under Mourinho.

Petr Cech's return cannot come soon enough and if he is able to play against Liverpool, that will be massive for Chelsea.

In my opinion, Cech is more important to Chelsea than John Terry for the simple reason that when you have a goalkeeper who dominates the six-yard line, it gives the rest of the team so much confidence.

The guy has been brilliant for two years and I think you can trace the start of Chelsea's problems to when he got injured.

Meanwhile, Arsenal will have to cope without the suspended Gilberto, who gives their defence vital protection in the same way Claude Makelele does for Chelsea.

They are certain to miss him against a high-flying United, who are just crushing everything that is put in front of them.

It is a very difficult game to call but, as I always say, these things come down to pressure and, in that respect, the ball is in Chelsea's court.

If they can beat Liverpool on Saturday, United will be under huge pressure to match that result at the Emirates Stadium on Sunday.

If Chelsea get a bad result, the pressure is lifted and United could finish a massive weekend with a nine-point lead in the Premiership.

Coupled with United's superior goal difference, that would be a massive gap for Chelsea to close.