The Nigeria winger has been signed from CSKA Moscow.
He said: "It's all been very quick. I'm happy and very excited to be part of this family and I'm looking forward to doing many, many great things that we can achieve here.
"So I'm very happy and excited.
"For a club like this to be interested in me is something huge. From the moment my agent told me that they were interested, I was happy and excited about what was about to happen. Communication has been easy and I'm happy that everything has gone the way it has."
Ejuke added: "It's special to be the first Nigerian here. I think I feel good being part of this team and I'm looking forward to seeing what I can bring to the team. I hope I can come back with Nigeria as well because obviously it's always nice to represent your country, so I hope it's time to do it again and I'm really looking forward to it as well."