Former Franklin High School and Lipscomb University basketball star Garrison Mathews was on the outside looking in as an NBA free agent this summer. 

Though, as the fall gets going, the shooting guard has found his new league home. 

NBA insider Shams Charania reported Friday that Mathews had signed a one-year, non-guaranteed deal with the Boston Celtics. 

After spending two years with the Washington Wizards where he played in 64 games with 24 starts last season, Mathews will join new Celtics coach Ime Udoka and a roster with stars like Jayson Tatum, Marcus Smart, Jaylen Brown and Al Horford. 

Last season, Mathews averaged 5.5 points a game and shot 40.9% (38.4% from the three-point line, his longtime specialty). He averaged 16.2 minutes per game.

His season high for scoring last year with Washington came against the Miami Heat in a loss on Jan. 9, where he netted 22 points. 

He might've returned to the Wizards, but the organization parted ways with head coach Scotty Brooks this summer after his contract expired. The team hired Wes Unseld Jr. in his stead. 

Mathews joins the Tennessee connections in Boston, with former Volunteers stars Josh Richardson and Grant Williams and former Commodores standout Aaron Nesmith on the roster. 

He'll join a guard position featuring Tatum, Brown, Smart, Nesmith, Richardson, Dennis Schröder, Payton Pritchard and Romeo Langford. 

The team just signed veteran guard Theo Pinson as well. 

The Celtics are coming off a 36-36 season that saw longtime coach Brad Stevens take a role in the front office and Udoka, a former Brooklyn Nets assistant, hired to take over the program.

Boston was the seventh-seed in the Eastern Conference last fall and lost its opening series to the Nets. They knocked off Mathews' former team, the Wizards, in a play-in game, 118-100

While he's not a lock to make the final roster, Mathews will have time during training camp and through exhibition games to prove to the Celtics he's worthy of rotational minutes this season. 

Preseason begins for the team Oct. 4 vs. the Orlando Magic at home, while the regular season begins Oct. 20 at Madison Square Garden vs. the New York Knicks.