Martial has often played wide in the early years of his career, but has now become United’s No.9.
Ighalo, 31, has played as a striker in Nigeria, Norway, Italy, Spain, England and China.
“Odion is a seasoned No.9. He’s played that position his whole career whereas Anthony has played more out on the wing.
“Odion is helping on the training pitch, in terms of his movement, hold-up play and just being himself. Anthony is learning off an experienced centre-forward,” Solskjaer told Sky Sports.
Martial has already scored 19 times this season, the best tally ever in his career.