Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: Rio Ferdinand believes Louis van Gaal's decision to return Wayne Rooney to his favoured attacking role has led to the Manchester United's upturn in performance levels. Writing in his column in The Sun ahead of the Manchester derby on Sunday, Ferdinand, now at Queens Park Rangers, revealed his belief that Rooney playing as a striker is fundamental to United hitting fifth gear. He praised Van Gaal for moving his captain further up the field after a spell in the centre of the pitch at the start of the year but admitted the return to form and fitness of Ander Herrera, Marouane Fellaini and Michael Carrick has also been important.Rio Ferdinand says Manchester United need Wayne Rooney in attackHe believes Rooney's form has been key to their upturn in performancesFerdinand said United's 2-1 win at Anfield shows they are 'on to something'Manchester United vs Manchester United: The expert view of the derbyCLICK HERE for all the latest Manchester United news 
 Question:Ferdinand also pointed to the return of midfield player Michael Carrick (left) as a help to _.

Manchester United