Michael Carrick's Fitness Is Crucial for Manchester United's Run-in

Manchester United's excellent form in recent weeks has been clear for all to see, and Michael Carrick has played an important part in that.

Louis van Gaal has built the English midfielder into the heart of his current system. Playing at the base of midfield, Carrick allows Ander Herrera and Marouane Fellaini license to create triangular overloads down either flank in conjunction with their respective wide-forwards and full-backs.

Correlation is not causation, as any statistician will tell you, but as the Guardian's Barney Ronay pointed out, United have only lost once with Carrick in the side all season. 

It was in the wake of the chaos caused by Carrick limping off injured that Sergio Aguero scored Manchester City's late consolation goal in United's 4-2 win on Sunday.

Given Carrick's central role in United's current success it is no surprise that Ronay went on to assert: "Certainly Van Gaal, who knows a bit about team building, will be desperate for Carrick to recover from injury in time to face Chelsea at Stamford Bridge on Saturday."

According to Stuart Mathieson of the Manchester Evening News, Carrick will be given "every chance to confirm his fitness" ahead of the Chelsea game. 

Given how functional United's midfield has been of late, it is easy to see why Van Gaal would be "desperate" for Carrick's inclusion in the starting XI on Saturday evening. If he is absent, the Dutchman will either have to change his system or replace Carrick with Daley Blind, and replace Blind with either Luke Shaw or Marcos Rojo.

Rui Vieira/Associated Press

Either option looks like something of a gamble. Blind has done well in United's midfield on occasion, notably against Sunderland at home, but that was a game in which United totally dominated possession. Blind's role in United's midfield has not been at the base of a three, either.

He has played at the base of a diamond or as part of a 5-3-2 with two other midfielders playing narrower than Herrera and Fellaini are currently.

Where Blind has excelled is at left-back in the current system. While his relative lack of pace can be exposed—as it was on occasion by Jesus Navas on Sunday—his link-up play with Fellaini and Ashley Young has been superb. It is not clear whether Rojo or Shaw have the footballing intelligence to fit into the system there as well as Blind is.

Jon Super/Associated Press

Blind has also been part of the back-four's collective positional discipline, which Jamie Carragher drew attention to on Sky Sports' Monday Night Football this week.

The system is being executed superbly by the current personnel, and Carrick's exclusion could have something of a domino effect. Blind is probably a downgrade on Carrick in the middle of the park, and whoever replaces Blind at left-back is—on current form—likely to be a downgrade on the Dutchman.

While United's "click" has surely emerged too late to warrant talk of a push for the title, there is still plenty to play for this season. Not all Champions League qualification spots are created equal. Finishing fourth will require a play-off to qualify for the group stages, against some potentially tough opposition.

As well as automatic qualification for the group stages, third spot also comes with an improved financial reward, due to the somewhat arcane rules governing distribution of Champions League revenues.

Chelsea is not United's last tough challenge of the season, either, with an away trip to Goodison Park and a home tie with the resurgent Arsenal also on the docket. It is thus crucial that United maintain their performance levels if they want to finish the season on the same kind of high they are currently riding.

Ronay further highlighted Carrick's influence on Sunday: "Against City Carrick had 71 touches of the ball, more than any other midfielder or attacker. He made more passes than any other player—almost twice as many as Fernandinho—with the highest completion rate of any of the starting 22."

Those kind of numbers are a nice illustration of just how vital Carrick has been to United's recent performances. They need him during the run-in.