Race for places has helped United - Brown
Wes Brown is convinced the extra competition for defensive slots at Manchester United has fuelled the Red Devils' impressive late charge.
United tackle Sunderland on Friday looking to record a 10th successive Premiership win and cut Chelsea's lead at the top to just four points ahead of the champions' tough trip to Bolton.
While striking trio Wayne Rooney, Louis Saha and Ruud van Nistelrooy have been taking most of the plaudits for United's outstanding recent form, Brown believes the defence deserves some credit too.
With only six goals conceded in those nine wins, Sir Alex Ferguson's men have a better defensive record than Chelsea over the same period.
Brown believes a major factor in the miserly tally is the jostle for first-team places caused by the transfer window arrival of Nemanja Vidic and Patrice Evra.
The England man is one of the players to suffer, having seen his return to first-team duties after a recent groin injury blocked by Vidic's impressive recent displays.
But, with Gabriel Heinze ready to make his senior return after seven months on the sidelines, Brown reckons the added competition can only aid United's quest to overhaul Chelsea.
'We have so many players in so many different positions now, the manager has a great choice,' the 26-year-old Mancunian told MUTV.
'Nemanja has been excellent, Mikael Silvestre has been playing really well at left-back and Gabriel Heinze is back in training and looking great, so everyone is fighting for positions.
'That is what has seen us step up in recent weeks.
'You have to show something on the pitch, otherwise you will be dropped.'
Brown could only make the bench on Sunday as United swept past Arsenal to keep themselves in the title chase.
There is a real belief among the Red Devils camp they could still pip Chelsea on the line, although they do need a big favour from Bolton at the weekend.
Brown, though, maintains United's focus must be on their own form over the final five games of the campaign.
'We are playing well at the moment,' he said. 'We just have to keep winning, that is the most important thing.
'Our confidence is high and hopefully we can keep it going for the last few games of the season.'