In his regular BBC Sport column, Robbie Savage looks at the key players and tactics that could decide the midweek games involving some of the teams at the top of the Premier League table.

Arsenal were hoping Mesut Ozil would inspire them after spending £42m to bring him from Real Madrid, but he seems to have lost some of his early-season sparkle. Both team and player have something to prove against Manchester United on Wednesday.

And, while Manchester City have drawn a blank in their last two games, Liverpool's attack continues to look lethal. They will take a very different approach to United when they try to break down Fulham's defence at Craven Cottage.

Ozil off colour for Arsenal

If Chelsea's Eden Hazard is peaking at the right time to make a decisive impact on the title race, Mesut Ozil has seen his form head in the opposite direction.

He is in the team for his attacking talents - to score goals and make chances - because, as we saw when Liverpool thrashed the Gunners 5-1 at the weekend, he does not contribute defensively.

I highlighted on Match of the Day that he made only four touches in his own half at Anfield, and that after losing possession he did no more than jog back.

He has never really done anything that different for the Gunners, though, because he has hardly done any defensive work since moving to Emirates Stadium.

That would not be a problem if he was still producing going forward, but he isn't.

Although Ozil made a good start after his £42m move from Real Madrid with four goals and six assists in his first 12 Premier League games, he has managed just two assists and no goals in his last eight league appearances.

Ozil for Arsenal Premier League First 12 games of 2013-14 Last 8 games of 2013-14 Mins played 1048 672 Goals 4 0 Shots 16 3 Assists 6 2 Chances created 34 22 Goals involved in 10 2

He had 45 touches against Liverpool, while his average in the Premier League this season is more than 80 per game.

Ozil has to show against United on Wednesday that he can have an impact in a match against another leading team. He needs a big performance and so do the rest of the Arsenal team.

I think we will see one too. When Arsenal lost 6-3 at Man City in December they went on a 10-game unbeaten run in the league that ended at Anfield at the weekend.

What will help them is that United are terrible defensively at the moment.

United midfielder Darren Fletcher said in an interview last week that their central midfield two were not in the team to create; they were there to do defensive work.

They certainly did not do that against Fulham. There was a catalogue of errors for Steve Sidwell's opening goal, including one by Fletcher, who did not track him because he thought he had passed him on to a team-mate.

Nemanja Vidic had gone walkabout and there was a massive hole in the middle of their defence, which Patrice Evra did not cover.

If Arsenal can get the ball moving in midfield like we know they can, they should be able to make the most of the lack of pace in the spine of United's side. United are there to be got at, and Arsenal will win at Emirates Stadium.

Liverpool attack cleverer than aimless crossing

We saw Manchester United's attacking limitations against Fulham on Saturday when they put 81 crosses into the box, 71 from open play.

That was the most in a single game in the Premier League since records began in 2006, and far more than the top-flight average this season of 23 crosses from open play.

United must get the best out of Wayne Rooney, Robin van Persie and Juan Mata, but they will not do that by putting cross after cross into the box.

Contrast that approach to how Liverpool came at Arsenal on Saturday.

They also used the flanks, almost as much as United, but made only six crosses in open play.

Unlike United, Liverpool were not putting aimless balls into the box; they were picking out their men.

With Luis Suarez, Daniel Sturridge, Raheem Sterling and Philippe Coutinho in their team, they come at you from all angles and stopping them will be a very different challenge for Fulham to the one they faced at Old Trafford.

The Cottagers will have to adopt a similar approach to Sunday, however, and stay tight and defend in numbers. If they go at Liverpool, they will get ripped apart.