Ander Herrera explains why he wears the no.21 shirt at United
21 is quite an unusual shirt number for a midfielder.
The Spaniard said: "I used to wear No.8 when I was in Zaragoza in my first club.
"I was two seasons in La Liga, in the first division, and then I moved to Athletic Bilbao and I remember I had the 21, 23 and maybe 17 was free.
"I took 21, I spent three fantastic seasons at Athletic Bilbao, things went very good for me, so I just kept it."