Despite Arsene Wenger's famously erratic eyesight, even the Arsenal manager will see the irony of Cesc Fabregas's knee injury occurring in the same week as Lassana Diarra completes a £20million move to Real Madrid and Steve Sidwell and his Aston Villa team-mates aim to extinguish the Gunners' title hopes once and for all.

For Diarra and Sidwell were, of course, once under the tutelage of the Frenchman and have since developed into exactly the type of combative competitor many feel the club need to sign in January.

Mathieu Flamini, Gilberto, Edu and perhaps even Patrick Vieira also rank as central midfielders who left before their worth had expired, despite Wenger's assertion he could prosper with Denilson, Fabregas and a young supporting cast in the engine room.

Sidwell's increasingly impressive displays - arguably none more so than in the Villa side that beat Arsenal 2-0 at Emirates Stadium last month - have helped form the heartbeat of a Villa side who can rightly claim to be expanding the 'Big Four' into the Big Five.

"Sidwell is a good all-round midfielder," said Wenger of the 26-year-old he allowed to leave in 2003.

"He is good defending, a hard defender and goes into the box well. He is a bit similar to (Frank) Lampard in his game. I'm happy he has had a good career because we always knew he would make a professional.

"It was difficult to assess at what level [he would play] because when he was younger he had technical problems but he has improved that side of his game and is now a very good player."

Having watched his development from afar, Wenger could be forgiven for regretting Sidwell's departure but he said: "You can only play with 11, it's as simple as that.

"The best 11 play and at the time he was not within that. Even in the squad, it was difficult for him to get on the bench.

"At some stage, for his development, it was better for him to go and play somewhere. We don't forget - if you look at players educated here at Arsenal Football Club you will see we have produced many good players."

Cynics would argue that a lot of those - Sidwell, Matthew Upson, David Bentley, Jermaine Pennant - are English and Wenger has failed to bring through talent from these shores, aside from Theo Walcott and Ashley Cole.

By contrast, five of the Villa front six that beat Arsenal were English but when asked to explain the imbalance, Wenger instead focused on Graham Poll's admission that referee Phil Dowd would have thought twice about sending off John Terry at Everton on Monday night because he is England captain.

He said: "I'm a football manager, not a passport manager. For me, I don't see where there is merit as a manager for playing with an English player or a South American. The comment from Poll, for me it was embarrassing. He says you have to consider that you are sending off the captain of the national team. What has that got to do with the rulebook?"

Wenger had no issue with Xabi Alonso's tackle on Fabregas, whose loss is unfortunate and statistical analysis indicates the 21-year-old will be sorely missed over the next four months.

A sample of the last 100 Premier League games from www.betterlogic.com, shows the Gunners lost 28 per cent of fixtures with Fabregas absent compared to just 13 per cent when he is present.

But perhaps equally telling is that Arsenal are more likely to score when he is in the side - 56 per cent of the matches involving Fabregas have included three Arsenal goals or more compared to 61 per cent yielding two goals or less without him.

Ultimately, Wenger's insistence that his squad is strong enough will now be tested to the limit. It is a measure of how far the Gunners have fallen - and equally the rise of Villa - that a win on Boxing Day would represent a notable scalp.