CLEVELAND -- LeBron James has faced Gregg Popovich in three NBA Finals, and on Saturday night he will play his 24th regular-season game against him, not to mention the uncountable number of San Antonio Spurs games he's watched.

In other words, the Cavaliers star has had plenty of time to form an opinion.

"I think he's the greatest coach of all time," James said Thursday, echoing comments he made last summer.

"You have to be sharp, mentally and physically, when you go against his ballclub. If you were an NFL player, it's probably the same as going against a [Bill] Belichick team," James said after scoring 21 points with 15 assists and nine rebounds in a 118-103 win over the Phoenix Suns. "What they're going to do, they're going to do and you have to try to figure it out." LeBron James says Spurs coach Gregg Popovich is the best coach in NBA history. AP Photo/David Banks

Popovich has often praised James over the years, but he also has spent a lot of time trying to devise a way to beat him. The defense he designed for the 2007 Finals forced James to change his training methods to become a better shooter. In 2013, James played one of the finest playoff series of his career to beat the Spurs for the title, the only time in six trips to the Finals that Popovich has been beaten. The Spurs beat James and the Miami Heat the next year.

James first got to know Popovich in 2004, after his rookie season, when the Spurs coach was an assistant for Team USA. James was part of the team that took Olympic bronze in Athens that summer. James has been studying Popovich ever since.

"To be able to do what he's done where the basketball has changed so much and he's been able to have a growth mindset and change with the game [is impressive]," James said. "We went from a league where it was inside out, where every time you came down it was throw it to the big, and then it goes to every time down pick-and-roll, and then it goes to every time down shoot a 3.

"Pop has been able to adjust every single time and still, for some odd reason, keep those guys under the radar. I don't understand it."