The 28-year-old has featured in only three matches for Scottish Premiership leaders Celtic this season, but remains an important figure in the Costa Rican national team.
Gamboa says he holds no grudges against Celtic boss Brendan Rodgers. He said: ''I have spoken to the manager and he understands the situation. I also understand his situation. I need to take care of myself. If they need me then I have to be ready. I'm just waiting.''
The lack of game-time this season will be a concern for the defender heading into the World Cup this summer. Costa Rica will face Brazil, Serbia and Switzerland at the group stages in June.
In a bid to be fully prepared for the tournament in Russia, Gamboa has brought a personal trainer over from Spain and is putting in the extra hours in the gym to perform at his best level for his country.
He said: ''I just have to make sure I am fit and I am ready for the World Cup. The good thing is that I know Costa Rica trust me a lot. The World Cup is a massive thing for me and that's why I'm doing all that I can. That's why I have being doing extra sessions after training. I have been working with this guy for the last two weeks and I will keep working with him until the end of the season. I need to think about myself now,'' he added.