Theo Walcott will miss the rest of the season and World Cup  due to a knee injury, which is a crushing blow for Arsenal  fans and their title chances.
Walcott  was Arsenal’s key player during the hectic festive period scoring five goals. He only returned from an abdominal injury and played his first 90 minutes away at Manchester City on 14th December, scoring a brace.
His form was much welcomed and came at a time Arsenal were starting to fade, with a draw against Everton and defeat against Napoli. Arsenal at times in the season played too narrow and didn't offer much pace on the wing. Theo was the answer to that, stretching the play and getting past opposition high-lines. His two goals against West Ham was proof of that, with 22 minutes left to play Walcott saved Arsenal and was at times was unstoppable.
"If Theo had stayed fit until the end of the season, I think he would have got Arsenal the title because his pace can stretch defenders." - Charlie Nicholas
Arsenal’s midfield is on par with Chelsea’s as the best in the league, but the Gunners have insufficient cover for a wide player with electrifying pace. His natural replacement, Alex Oxlade-Chamberlain, has been injured since August and should be back by the end of the month. Mikel Arteta, Aaron Ramsey, Jack Wilshere, Santi Cazorla, Tomas Rosicky and Mesut Ozil are not natural wide players who love to hug the touchline and have the ability to cut across the defence with pace like Walcott was able to manage.
With Olivier Giroud's ankle a worry, Lukas Podolski may have to carry the front-line and with no pace apart from Wilshere and Rosicky’s energy to support the wide areas, Arsenal may struggle. An option for The Gunners is a loan signing for Manchester United’s Wilfred Zaha, who is unsettled at United with Moyes in charge.
"Shocking news regarding Theo Walcott. I wish him a speedy recovery and hope he returns next season as good as ever." - Michael Owen