Boston Celtics fans can breath easier now. The C's and Marcus Smart have agreed to a 4-year, $52 million contract extension.

That averages out to about $13 million a year. It gives Smart and big bump in pay and it gives the team cost certainty.

Smart was a restricted free agent and did not appear to be getting many offers from other teams. The Celtics always had the chance to match on other offer. Smart also had the chance to accept a $6.1 million qualifying offer and become a free agent next year.

Now the deal is done and both sides seem happy.

"This is where I want to be, and I'm ready to put a green jersey back on and get to work," Smart said in a statement. "I'm determined to help my teammates bring another championship to the best fans in the world."

Smart averaged 10.2 points, 4.8 rebounds and 1.3 steals in 54 games last year. Many basketball observers say his tenacious defense offsets his shooting woes.