There was plenty of construction in and around the Air Canada Center this summer as the home of the NBA's Toronto Raptors and the Maple Leafs from the NHL underwent a spectacular multi-million dollar facelift.

But by far the most dramatic bit of team renovation was carried out by the Raptors' dapper general manager, Bryan Colangelo.

He effectively took a sledgehammer to his under-achieving squad and embarked on the type of massive re-build not often seen in professional sports.

All that remained was a cornerstone, two building blocks and a blueprint.

When training camp opened earlier this month only three players - Chris Bosh, Italian forward Andrea Bargnani and Spanish guard Jose Calderon - had been in camp the year before.

Toronto Raptors' Chris Bosh passes the ball in a preseason NBA game last Friday in Sioux Falls, SD. AP

But it is a sturdy foundation for Colangelo to build a playoff-quality team.

"It was a radical makeover," he told reporters. "We made the changes that we felt would make us a more competitive basketball team.

"I'm not one to under-sell and over-deliver. I always try to put a realistic view on things."

He admitted changes made last year had failed.

"It didn't work out, you can't always be right and I'm going to wear that on my resume," said Colangelo. "You look at the volume of change from where we were last year in training camp and three guys remain. Those three guys are going to be important parts."

Fan favorite

None more so than Bosh, who has blossomed into one of the NBA's premier power forwards and a fan favorite in a hockey-obsessed city.

But with the new season tipping off, Bosh has Raptors fans fretting as he seems intent on testing the free agent market next year along with fellow Beijing Olympic gold medalists LeBron James and Dwyane Wade.

In six seasons in Toronto, Bosh has had 62 teammates and made just two trips to the post-season, dropping out in the opening round both times.

A taste of playoff action has Bosh hungering for an NBA championship.

But after the Raptors finished last season 13th of 15 teams in the Eastern Conference - a massive 33 games back of the first place Cleveland Cavaliers - the four-time All-star is considering his options.

Certainly there will be no lack of suitors in pursuit of Bosh who averaged a career-high 22.7 points and 10.0 rebounds last year and looks ready for business this season. He comes to camp a chiseled 245 pounds after packing on 20 pounds of muscle.

With the sharks circling, Colangelo said: "My goal is to keep him here in a Raptors uniform long term and make it work because he is the right kind of person to have as a cornerstone or a franchise-type player.

"We're still in a situation where there is loyalty both ways, that relationship remains a positive."

He said: "I told him, I'm a big boy I can handle hearing you don't want to be here but don't lose sight of the fact that there has been that relationship and in the end we are still your best conduit to get the biggest possible contract and most money out there in a new deal."

Lured to Toronto

Twice named NBA executive of the year, Colangelo was lured to Toronto in 2006 after 15 years with the Phoenix Suns, arriving in the league's most northern outpost with a reputation sharper than his impeccably tailored suits.

Colangelo made an immediate impact as the Raptors improved an NBA-best 20 games in his first season in charge.

But last season, the magic touch disappeared.

Jermaine O'Neal and later Shawn Marion were brought in with great fanfare as the missing pieces to provide a playoff push but the result was a slide down the standings.

Sam Mitchell, coach of year in 2007, was sacked mid-season and replaced by unproven Jay Triano, the first Canadian to hold an NBA head coaching job. Another rebuilding project was begun.

"I always take it personally, I hate losing," said Colangelo. "I told everybody I have spoken to there is no one more disappointed than me with what transpired last season. I was embarrassed by it."

Colangelo's makeover was highlighted by a bold trade for Orlando Magic's All-star Turk Hedo Turkoglu in a slick three-team deal then added Italian guard Marco Belinelli and brought back Slovenian big man Rasho Nesterovic.

Hardnosed Reggie Evans was signed to bring some grit and toughness to a line-up labeled as soft. Athletic forward DeMar DeRozan and guard Jarrett Jack are also on board.

By most appraisals the Raptors have seen a huge upgrade in talent but it will take time to assess whether it produces the necessary chemistry.

Colangelo said: "The one thing I can do is sell hope. Right now selling hope is that we've got a revamped team, we've got solid players, we've got solid people, we've got a brand new coaching staff.

"Everything leading to this point feels very good."