The Martial mistake

After the sale of Robin Van Persie, and refusal to sign Falcao on a permanent deal, it became evidently clear that Van Gaal was planning to push Wayne Rooney forward to be United's main man on the attack.
 

A move that was welcomed by almost every body connected to United. Rooney, a proven goal scorer, enjoyed his best goal scoring season at United leading the lines, scoring over thirty goals, the season after Ronaldo left United for Real.

And so to a lot of fans and observers, Van Gaal was taking a step in the right direction.
To the amazement of many, united started the season lacking potency, vibrancy and goals. And guess the reported main culprit, it was Wayne Rooney. Stats and facts started rolling in about the number of games and minutes the Englishman had gone without a goal.
This was not helped by the sale of United's number two striker in Javier Hernandez. Though United were still grinding out results, there there was a clamour for Van Gaal to sign a striker, even though there were only few strikers that would fit into the United's goal scoring needs.
Out of the blues, Van Gaal signed Anthony Martial from AS Monaco, a teenager whose  best position was still unknown to the world was signed for over $30M, a fee that could still rise depending on other factors.

Martial's arrival at Old Trafford was welcomed, but there were scepticism about his move. how he would handle the pressure, and if he could solve the United's lack of direction in the final third.
The God of soccer couldn't have given Martial a better smile, and prepare a more befitting welcome party for the Frenchman at Old Trafford.
 

A well taken goal against arch rival Liverpool, that displayed all the fans wanted to see in a striker that could solve United's goal scoring problems. His composure is second to none, he's got strength, speed, tricks and can create something from nothing.
For once, United fans must have thought that was the end for the team's search for a striker.
And over the next few weeks and game, they were right. Martial brought the needed direction and goals to United's attack. Five goals and three assists in his first nine games, what more can you ask for.
 

But suddenly, Van Gaal seem to develop other plans for the developing striker. With Depay misfiring, and Herrera proving his worth, Van Gaal moved Martial to the left. A change that has reduced his effectiveness, and at the same time, return United to it's era of struggle for goals.
United have scored only one goal in its last three games, Martial being the team's last goal scorer against CSKA Moscow. A game he played on the left and scored with his first attack from the middle.
 

Rooney's continual struggle for goals means United's struggle for goals. Using players off position is one decision that has been common with the Van Gaal era at United. Last season, Di Maria, Fellaini, and a host of others were used in new positions by the manager. 

Almost everybody in the United squad, except the goalkeeper can play in at least two positions, good for some players, good for the team, but it inevitably reduces the effectiveness of some players. It is a habit that Van Gaal seems to have begin this season, and the earlier he realizes that Martial will be more effective for the United squad playing from the centre, the better for the team and its ambition.
 

Rooney has been struggling for form for a while, why not bench him or play him in the number 10 position, than sticking with him and hurt the team's title ambition.