By Larry Fine

LONDON (Reuters) - Miami Heat guard Dwyane Wade said on Wednesday he felt pangs of regret about missing the Olympics because of injury but felt worse for players that could miss the chance altogether because of an age limit being considered for future Games.

The International Basketball Federation (FIBA) has been exploring the possibility of following soccer's Olympic model with under-23 teams augmented by three exceptions, which ensures its World Cup is the preeminent world competition in the sport.

"It's not something right now that everyone smiles about because so many of us have been older and got an opportunity to play in the Olympics," Wade, 30, told Reuters.

"Especially if you go through four years of college, you get out, it might take you four years to get your legs under you in professional sports and now you're ready, you might be too old to play in the Olympics."

Wade was set to play on the U.S. team for his third Olympics but after winning the NBA title with the Heat found he required knee surgery and had to withdraw from the team.

Now in London, Wade was looking forward to watching his NBA colleagues do their thing as the men's competition swung into the quarter-finals stage.

"In one sense I'm a fan and I'm excited about the game and I want the U.S. to do so well, but in the other sense I know I should be on the team and it kind of hurts a little bit that I'm not there and not sharing the moment," he said in an interview at an appearance promoting Gatorade's sports science studies.

"But I'm excited for those guys, a lot of guys getting their first time to play in the Olympics and live out a dream come true. I've been able to win a gold medal (2008). I've been able to win a bronze medal (2004) as well, so I've been blessed."

Wade, who said his knee operation went well and that he was feeling great and excited about getting ready for the next NBA season, was philosophical about a possible Olympic age limit.

"Honestly, there's always change and you always adapt," he said. "The window of opportunity is very short and very small ... but I'm sure in the long run everybody will make adjustments.

"You got a lot of great guys that's in our league that wouldn't be able to play on the team. I don't know. Change happens and you have to adapt. The NBA is the best at that."

Wade was not so conflicted in his appraisal of the U.S. team's chances for repeating as gold medalists.

"They're still learning each other and they're just going to get better and better with each game, whether it's an 83-point win or whether it's a close win," he said.

"I think they're going to be their best at the end and I believe they're going to bring it home."

Wade suggested that more focus on the defensive end would make the U.S. mission much easier to accomplish.

"When an American team is playing defense, when they're playing aggressive, when they're getting in on the ball, being ball hawks, they're tough to beat," said Wade.

"When they're laying back and not doing that as much a team like Argentina can be down by one at the halftime," noted Wade, before adding with a smile, "and then they can turn it up like they did and score 43 points in the third."

Wade said he had been getting a special kick out of seeing his Miami team mate LeBron James put his all-round basketball skills on display.

"LeBron's been on cruise control. He's been doing whatever the team needs him to do that night," said Wade, adding that NBA Finals MVP James did not feel the need to prove his status in the basketball world.

"He has the ability to help the team win in many different facets of the game. Obviously, you see he can turn it on scoring-wise. He also can lead the team in assists, rebounds …

"I expect him to be a little bit more aggressive as they get closer to gold medal time. But aggressive for him is just being out on the court and being able to do what he does best - and that's everything."

(Editing by Nigel Hunt)