GB's penalty appeals were turned down and Senegal scored a late equaliser.
"I just tweaked my [knee] medial ligament but it should be alright... I felt physically quite good," he said.
"I do have to realise that I am two weeks into pre-season [training], as much as this is a competitive international.
"I think you could see [in] the last 20 minutes, half-an-hour, that it just caught us a little bit, but the great thing about football and the great thing about us is we've got another game coming up soon."
After their opening game at Old Trafford and Sunday's clash at Wembley, GB play their final Group A match against Uruguay at the Millennium Stadium in Cardiff.
"I'm a Liverpool fan, Liverpool's my club, but it's always an honour to play at Old Trafford... this place is truly a remarkable place to play football," Bellamy added.
"We're at another remarkable stadium at Wembley. I've lived in Manchester so I've been round this area, it's great to play here; I've lived in London and to get another chance to play at Wembley; and then I've got the chance to play in my home city.
"So it's great that the games are everywhere and people get to see them, and we have to be part of that as well and represent everybody.
"To come here and represent Great Britain and to represent my own country, which is Wales, it was special.
"It's something I've definitely wanted to be involved in and honestly it's just been unbelievable, every morning I wake up and I'm just enjoying it.
"Everything around the tournament I've never experienced and I'm really grateful; we have a great group of boys and the manager [Stuart Pearce] has been brilliant as well - this is just a special occasion, I've just been really fortunate to be a part of it."
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