The Spaniard made his debut under Pep Guardiola in 2008 and has been an integral part of Barcelona, playing over 500 matches for the Blaugrana.
Busquets has started 11 out of 18 La Liga games for the Spanish champions this season and the team has struggled when he has not been around.
He missed El Clasico due to illness and was also missing from the starting XI for the defeats against Levante, Granada and Athletic Bilbao.
Casemiro believes Lionel Messi is the best player in Barcelona, but his opposite number is as good as the Argentina superstar, as the 31-year-old provides cover to the defense.
“Along with Messi, Busquets has been the most important player at Barcelona in recent years,” the Brazil international told Mundo Deportivo.
“We talk about Messi, [Luis] Suarez or before about Neymar, but Busquets for me is the most important
“We talked about [Andres] Iniesta and Xavi, but he was always there doing the dirty work.
“He is one of the best defensive midfielders. Compared to me, he is different.
“He may not have the physical attributes like mine but he is always positioned very well – he is always well placed and that is very important.”
