Sun Jihai made seven appearances for the Blues in his first season and was a member of the China squad in the 2002 World Cup. But the defender had little chance to impress on the World stage after he picked up an ankle injury in the first game and had to sit out the rest of China's campaign which ended at the Group stages. The Manager believed that the defender was of Premiership class and fill the position of a utility defender playing anywhere across the back line or as a holding midfielder. With City Sun enjoyed his second spell in English football having spent a couple of seasons at Crystal Palace before returning to China in 1999.
Sun became the first Chinese player to score in the Premiership when he headed home the first City goal in their 2-0 win over Birmingham. It was the first match in which he had played right wing back for the club. He continued with impressive displays in that role denying Shaun Wright-Phillips a place. He scored his second of the season for the Blues at Sunderland in early December when they won 3-0.
A serious injury to his cruciate ligaments sustained in a tackle with Chelsea striker Eiður Guðjohnsen kept him out of play for most of the 2004/05 season. His contract was nearing an end but the club granted him an extension despite his injury. After recuperating and following a strict physical regimen devised by his father he managed to fight his way back into fitness and a place in the team but the 2006/2007 season was again set back yet again by another serious injury. Again he made a full recovery and returned to the City squad on February 10, 2007 against Portsmouth.
His last season with the Citizens also proved difficult injury wise and Sun only made 14 apperances under Sven Göran Eriksson. When Mark Hughes took over as Manager in June 2008 Sun was not offered an new contract and in early July 2008 he signed a 2 year deal with Championship side Sheffield United. Sun played 150 games for City, scoring 4 goals (including one in the UEFA-cup).