BOSTON – It's official. Joel Embiid has signed his five-year, $146.5 million extension, the 76ers announced Tuesday morning.

Embiid could earn $178 million if he meets the super-max criteria, which include making an all-NBA team or being named league MVP. The deal, however, is heavily salary-cap-protected should Embiid miss significant playing time because of injuries.

"I think I'm blessed," Embiid said of his extension. "I think I'm in an amazing position. That just shows you how much the team trusts me. I need to go out there and play, especially for the city of Philadelphia.

"But I was thrilled [to get the extension]. I was happy.  …I was amazed. I didn't know what to say."

Embiid played in only 31 games last season before the team announced on March 1 that he would need season-ending knee surgery. His last game was Jan. 27.

He missed the previous two seasons because of two surgeries to repair the navicular bone in his right foot. He also had a stress fracture in his back that kept him out of the Big 12 and NCAA tournaments during his lone season at Kansas in 2014.

The 7-foot-2 Embiid offers a total package of size, toughness, shot-blocking ability, strength, athleticism, quickness, and competitiveness. He's the most important part of the Sixers' hopes of turning "The Process" into a championship team. Without Embiid, the Sixers will have to rethink everything about the plan they've been working on for the last few years.

"Joel is a special basketball player, but he's a special human being; he's a special person," Sixers president Bryan Colangelo said. "You see just the way the team responds to him, the way the fans respond to him. He's one of these types that don't come along often.

"Again, we are talking about both what he does on the court, but what he also does off the court. He means a lot to what this organization has gone through."

The Sixers and Embiid's representation began discussing an extension on July 1. Embiid said he signed his contract on Monday, the day of his mother's birthday.