LAS VEGAS – Amir Johnson had a pretty good idea about which teams he might hear from on the first day of free agency.



And then came the call … from the Boston Celtics?



It was Danny Ainge striking first, letting Johnson know he has admired his game from afar for a long time and wanted him to be donning a Celtics uniform next season.



The two continued to talk and it didn’t take long for Johnson to realize that his free agency wasn’t going to last long.



Boston would be his new basketball home.



“They knew the kind of player I am and they had a lot of respect for my game,” Johnson told CSNNE.com while watching the Celtics’ summer league team in action on Saturday. “For me, it was a no-brainer. I was going to become a Boston Celtic.”



The team signed Johnson to a two-year, $24 million contract with the second year being a team option.



Johnson, 28, said he’s not worried about hitting the free agency market next summer.



“It’s not guaranteed, but the way I play and what I know I’m going to bring to the table, it’s guaranteed in my mind,” Johnson said.



His confidence comes from having played with frontcourt veterans in Detroit (Rasheed Wallace, Ben Wallace and Antonio McDyess).



All of them he says taught him the importance of being a good defender which he was told, would keep him in the league for many years.



They were right.



As the 56th pick in the 2005 NBA draft, Johnson’s career wasn’t expected to last this long.



Players selected that late in any draft have a relatively short NBA career. But Johnson, the last high school player drafted into the NBA, has for years benefited from his potential.



After he became a free agent following two seasons in Detroit, Johnson had only played a total of 11 games. And yet the Pistons found themselves having to out-bid the San Antonio Spurs to keep Johnson in the fold.



Potential is no longer what teams see in Johnson. Instead, he is a constant energy player whose impact on games goes beyond the box score.



The Toronto Raptors have a pair of Atlantic Division crowns to their credit with Johnson. There were others who contributed to that success, obviously. But no one disputes the fact that Johnson’s willingness and ability to defend, contribute on the offensive glass and provide the kind of hustle necessary to compete, collectively proved to be vital to the Raptors’ rise in the NBA.



But his days as a Raptor are a thing of the past now.



Instead, Johnson is focused on doing whatever he can to help Boston build off of their late regular season run that ended with a trip to the playoffs.



And unlike previous teams, Johnson will be looked upon for leadership from the outset.



“For me, it’s just a process of growing up, becoming a man,” he said. “I learned a lot as a kid playing with vets. Now it’s my time to be that veteran leader.”