The Icelandic playmaker, who makes his Swansea debut at Barnsley today, has been snapped up on loan for the rest of the season.
Sigurdsson, 22, shared a room with Newcastle's 15-goal hotshot Ba when they were at Hoffenheim.
He said: "Demba's doing all right, isn't he? He has certainly made a big impact and now I'd like to do the same.
"He's a good friend of mine who I speak to a lot. I know he's very happy with life at Newcastle. He told me the league is fantastic and he is loving it here."