LaLiga giants Barca have been engulfed in drama for much of 2020, following Lionel Messi's public declaration that he wanted to leave the club, Luis Suarez's contentious departure to Atletico Madrid and the appointment of Ronald Koeman as new head coach following Quique Setien's dismissal in the wake of an 8-2 defeat to Bayern Munich.
Messi ultimately remained at Camp Nou after it became clear he would be unable to exercise a get-out clause in his contract, while Koeman refuted Suarez's claim that he was forced out of the club.
Busquets – currently on international duty with Spain – holds strong views on the state of his club but suggested it would take a significant amount of time to discuss them all.
"One thing is what happens outside, which is not the best moment of the club," he told a media conference ahead of Spain's Nations League clash with Ukraine. "And another what happens in the field, which was not our best year and it shows at an individual and collective level.
"If I stopped to give my opinion carefully, it could be five or six hours.
"On the field it was not our best year. Football is a team sport and if you are not well collectively, you will not be individually. But it has already happened and we have a new opportunity. Things have changed and we hope it will get better."
Busquets started Spain's 0-0 friendly draw with Portugal on Wednesday and their 1-0 Nations League win over Switzerland three days later to take him to 119 caps since his debut in 2008.
He is seventh on Spain's all-time most capped list but sits a whopping 55 behind record holder Sergio Ramos, who is the only player in the current squad to have played more international games than him.
The 32-year-old has dismissed following Barca team-mate Gerard Pique into international retirement, though, and says he hopes to remain part of the Spain squad for the foreseeable future.
"I focus on going season to season," he added. "It is clear that I am no longer 20-years-old and I cannot look much into the future. I feel fine.
"It depends on each situation of each player. A new but peculiar season has begun. I hope I can last a long time in the national team."