LONDON, Dec 3 (Reuters) - Jose Mourinho made winning titles a habit for Chelsea's players when he first arrived in 2004 and three months into his second stint at Stamford Bridge he is urging them to rediscover it.
After a third of the Premier League season Chelsea are tucked in four points behind leaders Arsenal but Portugal's Mourinho admits there is "a lot of progress to be made".
With eight matches in December, starting at struggling Sunderland on Wednesday, Mourinho knows it is crucial Chelsea maintain the pressure on their title rivals.
"There are things in the job that are not easy, and one of those things is to make the pressure of fighting for the title become something natural, something the players accept in a positive way," Mourinho told a news conference on Tuesday.
"Here we have some people that have won the title before but not for quite a long time, and when you don't win it for quite a long time you forget it.
"We have other people that have played in clubs that are not used to fighting for titles, it is just about doing fantastically today and not worrying about tomorrow or any big responsibilities.
"You have to learn how to live with the pressure of trying to be top of the league, how to fight until the last moment, knowing that every detail of every game can make a difference in the end. It's a process, not something you do with a click."
Mourinho said six teams were chasing the title this season, including champions Manchester United who are nine points adrift of Arsenal in eighth place.
"There is a lot to play for in December and January, we will see if one of the top six opens a real gap," he said.
"We can't speak about favourites but all the six teams are title contenders."
Chelsea could have Samuel Eto'o back on Wednesday after the striker recovered quicker than expected from a hamstring injury sustained in the Champions League defeat by Basel last week.
However, playmaker Oscar and defender David Luiz are unavailable.
"Eto'o is back training with the team," Mourinho said.
"I will have to see today but he looks fine. There is a chance he can play tomorrow." (Reporting by Martyn Herman, editing by Ed Osmond)