Sol Campbell has admitted the details of his return to Arsenal still need to be sorted out after playing for 45 minutes for the Gunners' reserves last night.
Campbell, who last featured for Arsenal in the Champions League final in 2006, played the first half of the reserves' 4-2 win over West Ham.
But the 35-year-old, who left Highbury for Portsmouth in the summer of 2006, has been training at the Gunners' Hertfordshire base since quitting Notts County.
Campbell -- capped 73 times by England, including a spell as captain and playing at three World Cups -- was keen to resume his career as quickly as possible after settling his contract dispute with League Two outfit County.
He could be in the Arsenal squad for the Premier League trip to Bolton on Sunday, but he first needs to sort out his contract in north London.
Campbell said: "There are still a few technicalities to iron out, but I have signed for Arsenal until the end of the season, and it's fantastic, great, marvellous. The old enthusiasm is back."
He added: "I'm ecstatic, really, to be back at Arsenal, and I have worked bloody hard to get there."
Campbell admitted he had a lot to thank Arsenal manager Arsene Wenger for.
"Arsene Wenger has been an inspiration," he said. "He has watched me closely after letting me train at Arsenal for nearly two months now.
"He's not stupid -- he wouldn't have taken me back if he didn't like what he has seen, and I have worked and worked. I do believe I can contribute.
"I really have my confidence and fitness back and I believe I can make a big, big contribution.
"There is fantastic quality all around the pitch within this Arsenal team and I want to be part of it, and I will make a big push to try to do that, but it's little steps at a time."