As well as the familiar faces of his old Hornets teammates, Ighalo will be reunited with compatriot William Troost-Ekong.
“Ekong is a nice guy, I know him from the national team, and he played in Udinese too, like I played in Udinese,” said the 31-year-old.
“Before he came to Watford, he sent me messages saying Gino wanted him to come to Watford. Gino told him how I came from Granada to help the team gain promotion to the Premier League and wants him to do the same thing.
“I told him he had to go to Watford, that Watford is one of the best family clubs. I played there for two-and-a-half years and had an amazing time, they took care of me and had no problems. He said okay and that he would think about it.
“I’m happy for him and happy he’s doing well, that’s the most important thing. I hope Watford keep doing well and gain promotion to the Premier League because that’s where they belong.”