Asamoah Gyan is delighted to be joining Ghana teammate John Mensah at Sunderland.
Gyan has made a £13.5million switch from French club Rennes.
"Quite unfortunately, when I joined Rennes he left only ten days later to sign for Lyon," Gyan told safc.com. "I have already met him here and I have played with him in the national team for over seven years.
"He is like a big brother to me and is always advising me. He is a great guy off the field as well as on it.
"He is a joker - he knows me well and I am a joker too, a big one.
"We joke together a lot when we are in the national team. The atmosphere here is very important to me."