David Luiz, midfielder?

A year ago, David Luiz was being used as a somewhat erratic defensive holder as Chelsea, under interim management, took the Europa League by storm. Eight months ago, Jose Mourinho rather emphatically dismissed the idea of the centre back being used in such a manner during his tenure. And on Saturday, the Brazilian paired up with Nemanja Matic in central midfield to help the Blues conduct a 6-0 slaughter of Arsenal.

What's changed?

Many fans and analysts have been asserting that David Luiz should play as a defensive midfielder more or less since the moment he arrived in London. The high profile errors combined with erratic discipline mean that his suitability to play at centre back has been in question for years, but he was obviously too talented to drop entirely. But defensive midfielder might be the single most demanding position on the pitch in terms of focus, and focus... well, let's charitably say it's not David Luiz's game.

And yet three of our best performances this season -- the home wins against Arsenal and Liverpool as well as the amazing 1-0 victory at the Etihad -- have come with David Luiz in the centre of the pitch. He hasn't changed much, of course: despite Mourinho's presence he's still as silly as ever, but he's turning into an absolute beast in the centre of the pitch, and could well be our first-choice option in dealing with Paris Saint-Germain in the Champions League.

What has changed is the context in which he plays. Gary Cahill's emergence as a dependable centre back means that David Luiz isn't physically required to partner John Terry, freeing him up to be used elsewhere, and the acquisition of Nemanja Matic in January* has given Mourinho the option of using the Brazilian in a freer role in midfield.

*It's worth noting that David Luiz also had a good game alongside first Frank Lampard, then Ramires during the 2-1 victory against Liverpool.

Saturday's match against Arsenal was a devastating reminder of just how effective the Matic-David Luiz partnership can be. Both are highly mobile, physical players with the technique keep the ball and the vision to spark the attack. Matic also possesses the tactical discipline to cover for his sometimes-wayward companion. The Gunners fielded a midfield trio of Mikel Arteta, Alex Oxlade-Chamberlain and Tomas Rosicky; they were bullied off the ball at every turn. The headlines will go to the attacking players, but it was the midfield from which Arsenal's collapse propagated.

Giving David Luiz license to roam in midfield, with a dedicated defensive player backing him up, is producing extraordinary results against top sides, and I can't imagine he'd slow down much against the bottom feeders. Putting him in a position to play like a Yaya Toure or an Arturo Vidal allows him to shine without being overly worried about his more erratic tendencies, and whenever Chelsea have done so they've had amazing results.

With Terry and Cahill overtaking the Brazilian in the centre back hierarchy and the midfield still a little weak despite Matic's addition, it feels very much like the David Luiz-Matic pairing could be the future. Assuming he doesn't get himself in disciplinary trouble as the result of having a freer role, Chelsea might finally have found the place that makes the most of his talents while masking his obvious flaw.

David Luiz: Midfielder.