Judging by his body language, you would never think Chelsea is only two points off the top of the Premier League table.

After an extra-time defeat to Sunderland in Tuesday's Capital One Cup quarterfinal, Jose Mourinho cut a bedraggled figure, a strange mixture of irritability, weariness and defiance. "We may have to take a step back in order to be more consistent at the back," he said. "It's something I don't want to do, to play more counterattacking, but I'm giving it serious thought. If I want to win 1-0, I think I can, as I think it's one of the easiest things in football. It's not so difficult, as you don't give players the chance to express themselves."

Since the beginning of November, Chelsea have played six away matches. They beat West Ham United comfortably enough in the Premier League, but other than that, Mourinho's side have lost to Basel (1-0) in the Champions League and to Newcastle (2-0) and Stoke (3-2) in the Premier League. Chelsea did beat Sunderland 4-3 in a chaotic league match, but the vulnerability evident then was exposed on Tuesday. Nor have Chelsea been especially impressive at home, salvaging a draw against West Bromwich Albion with a late penalty and struggling to a 2-1 win over second-bottom Crystal Palace on Saturday. Victory at Arsenal on Monday would take Chelsea at least level at the top -- depending on what Liverpool do at home to Cardiff on Saturday -- but the Blues enter that game in a state of uncertainty.

Mourinho has, by and large, stuck to the 4-2-3-1 formation used last season by Roberto Di Matteo and Rafael Benitez. It is logical enough; the squad have been set up to play that way, with a glut of attacking midfielders, the summer influx presumably intended to combat the fatigue that Benitez's side was constantly battling towards the end of last season. And Mourinho tended to use a 4-2-3-1 at both Internazionale and Real Madrid .

From the moment he arrived, though, Mourinho has been looking to play down expectations, claiming that this is not his type of squad and that this season will be one of transition. That seems to be the main reason Juan Mata has been such a peripheral figure, although he has come more into the fold recently, starting nine of the sixteen league matches this season. The implication of Mourinho's words on Tuesday, though, is that he is not merely considering a more defensive, more reactive approach -- he has, after all, said that winning 1-0 is "the easiest thing you can do in football" -- but also a change of shape, perhaps back to the 4-3-3 he used so successfully in his first stint at the club.

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Already this season, Chelsea have let in 18 goals in the league, three more than they conceded in the entirety of 2004-05, when they won the league in their first season under Mourinho, so there is obvious cause for concern. A shift to 4-3-3 would not alter the strange laxity at set-pieces Chelsea have suffered recently, but a switch may give Chelsea greater control of midfield -- not necessarily in terms of possession, but in holding the opposition at arm's length and thereby protecting the back four.

The problem is personnel. John Obi Mikel, a Mourinho favorite, could sit deepest of the three midfielders, with Ramires to his right and Frank Lampard to his left, and Michael Essien could crank up his ageing body to cover. With Marco van Ginkel out with an ankle ligament injury there are few other options, however, Mourinho dismissed the possibility of playing David Luiz in midfield. That presumably explains why Chelsea have been linked so strongly with a January move for Inter's dynamic midfielder Fredy Guarin.

While there is a dearth in terms of central midfielders, a switch to 4-3-3 would decrease the opportunities for Chelsea's array of creators. With Mata, Willian, Oscar, Kevin De Bruyne, Andre Schurrle and Eden Hazard competing for three spots, there has been an inconsistency of selection that seems to have led to a lack of fluency; reducing the number of available slots to two would only worsen the problem and it may be that De Bruyne leaves, probably on loan, in January. Given Chelsea's next four games are against Arsenal, Swansea, Liverpool and Southampton, all sides that like to dominate the ball, switching to a more reactive strategy makes some sense, so long as the squad can cope.

"Now is an important period for all of the squad -- everyone has a role to play and a contribution to give," Mourinho said earlier in the week. "Every player will be important when we have so many games and competitions to play."

Arsenal looked exhausted in losing 6-3 to Manchester City last Saturday, but they have had nine days to recover -- thanks in part to Chelsea, which beat them 2-0 in the League Cup fourth round at the Emirates in October -- and should be fresh. Yet Mourinho insists league positions count for little in January.

"I like the fact we will go there with this distance (between the teams), because it brings even more ingredients to the game," he told Chelsea TV. "However, I don't think in this league it will become a crucial game, if we leave Arsenal with five points difference or top of the league. I don't think it will make a big difference in terms of what is going to happen in the future because the league (this season) is like this."

Arsene Wenger has never beaten Jose Mourinho in nine games as manager, another subplot in a Monday night fixture rammed with them. Both sides have flaws, yet either could end up top of the table at Christmas.

FOXSoccer.com's newswire services contributed to this report.