Odion Ighalo's former boss Quique Sanchez Flores has warned it may take up to a month for Manchester United's new signing to reach his peak after completing a shock return to the Premier League.
Sanchez Flores was Ighalo's manager at Watford when the Nigerian struck 17 goals in a season, before also coaching him for a short time at Shanghai Shenua in China.
The Old Trafford side will be hoping the 30-year-old can rediscover that form this season, but Sanchez Flores warned that standards between China and England differ greatly.