Both doubt it will happen again because of Scottish, Welsh and Northern Ireland concerns that a single British team might jeopardize their places in global football.
"I honestly don't believe it will happen again," said former England defender Pearce.
Britain plays Uruguay on Wednesday at Cardiff, Wales, and needs to avoid defeat to make it through to the knockout phase. Uruguay needs to win to stand a chance of progressing.
Britain has not played in the Olympics since 1960 because of the political opposition to the idea of a unified squad.
Britain is playing this time around because it is hosting the event and didn't need to go through qualifying.
The team would have to take part in qualification if it wanted to compete in Brazil in 2016. That would require a greater level of commitment, as well as a permanent administrative set up. Currently, most players in both the men's and the women's teams are English because of opposition from the other home nation's football associations.
Bellamy also said he believed 2012 would be the last time a British team competed.
"My own experience has been outstanding," he said. "Would I like other players to get this opportunity? Yes, of course I would. But there is so much with qualification. How would that go?"
Olympic men's football is an under-23 competition with three older players allowed in each 18-man squad. Bellamy, a former captain of the Welsh national team, is one of the older players. He, along with fellow Welshman and Manchester United Star Ryan Giggs, have been the standout players in the British squad so far. The two players have scored a goal apiece, each off the other's crosses, and will be integral if the team is to win a medal.
On Wednesday, Bellamy faces off against Liverpool teammate Luis Suarez and returns to his home town of Cardiff. "I've played in Manchester and in London at Wembley, but for me Cardiff is a fitting place to place to play our last group game," he said. "And hopefully it won't be our last one."