The NBA has shifted away from the tried and tested formula where the Center position was always the foundation of a successful NBA team. While defensive Big Men are still key pieces for NBA teams, mobile centers who can shoot from the outside and have an aptitude for pick and roll situations are now being given the priority. Here are 5 big men who played for NBA champions that are still unsigned for the 2017-2018 NBA season.

Joel Anthony (last team, San Antonio Spurs)

Joel Anthony has had a relatively successful career in the NBA. The 35-year-old UNLV product won 2 NBA titles with the Miami Heat and has career averages of 2.2 points, 2.8 rebounds, and 1.1 blocks per game.

Anthony played for the Miami Heat (2007-2014), the Boston Celtics (2014), the Detroit Pistons (2014-2016), and the San Antonio Spurs (2017). While Anthony is considered an undersized center and past his prime, the longtime member of Canada's National Team can still play valuable minutes for NBA teams looking for a traditional big man.

Andrew Bogut (last team, Cleveland Cavaliers)

Andrew Bogut is a 12-year NBA veteran who won a title with the Golden State Warriors during the 2014-2015 season. Bogut, the former number 1 overall pick by the Milwaukee Bucks, was also a member of the Warriors team that won an NBA record 73 games. The Australian center started last season with the Dallas Mavericks but was traded and subsequently waived by the Philadelphia 76ers.

The Cleveland Cavaliers then acquired Bogut to shore up its bench. Barely a minute into his Cavs debut, the longtime Australian National Team member suffered a season-ending injury. The latest reports suggest that Bogut is nearing NBA form and is in negotiations with at least 4 NBA teams for a possible comeback. According to Fox Sports, the Boston Celtics are reportedly interested in acquiring the Melbourne native.

Boris Diaw (last team, Utah Jazz)

Boris Diaw is a 14-year NBA veteran who helped the San Antonio Spurs win the NBA title in 2014. The 35-year-old was awarded the NBA Most Improved Player award in 2006. The Frenchman played for the Atlanta Hawks (2003-2005), the Phoenix Suns (2005-2008), the Charlotte Bobcats (2008-2012), the San Antonio Spurs (2012-2016), and the Utah Jazz (2016-2017).

He averaged 4.6 points, 2.2 rebounds, and 2.3 assists in 18 minutes per game for the Jazz last season. Diaw is a versatile big man who can play multiple positions and can still play meaningful minutes for any NBA team.

Festus Ezeli (last team, Portland Trail Blazers)

Festus Ezeli is a 3-year NBA veteran who helped the Golden State Warriors win the 2015 NBA title. He was also a member of the Warriors team who set the NBA record 73 wins. The Nigerian last played for the Warriors during the 2015-2016 season and was signed by the Portland Trail Blazers. Ezeli never saw action during his one-year stay in Portland due to injuries. The big man averaged 4.2 points and 4.3 rebounds in 14 minutes of action for the Golden State Warriors.

Even with his injury history, acquiring the athletic big man is a low-risk gamble for contending teams since Ezeli has experience playing in big-game situations.

Tiago Splitter (last team, Philadelphia 76ers)

Tiago Splitter is a 7-year NBA veteran who won an NBA championship with the San Antonio Spurs during the 2013-2014 season. For his career, he averaged 7.9 points and 5 rebounds per game. Splitter was a valuable backup center for the Spurs especially during their championship runs against the Miami Heat. The Brazilian was traded to the Atlanta Hawks in 2015 and was traded to the Philadelphia 76ers on February 22, 2017. The Brazilian big man has 2 Spanish League titles, 1 Spanish League Finals MVP, Spanish League MVP, and 2 Spanish Super Cup MVPs. The 32-year-old Splitter may have lost a step, but he can still be a valuable backup for NBA teams.