Tim Duncan’s contract expired at 11 p.m. on Saturday night making him a free agent for just the third time in his 15-year NBA career.

In 2003, Duncan opted out of his deal with the intention of signing a new one with the San Antonio Spurs.

Declaring himself a "Spurs for life", the 36-year old forward will likely stay with the Spurs, the only question is, for how long and how much. 

“I don’t see him not having a future with the franchise,” coach Gregg Popovich said of the two-time league MVP and four-time NBA champion.

To give the Spurs a little hint, multiple reports indicated Kevin Garnett was planning to sign a three-year, $34 million deal to remain with the Boston Celtics.

Statistically, the two big men were remarkably similar last season.

Garnett averaged 15.8 points and 8.2 rebounds in a little more than 30 minutes per game. Duncan posted 15.4 points and nine rebounds in 28 minutes.

Howver, Spurs general manager R.C. Buford declined to publicly discuss negotiations with his star power forward.

“That’s not something we would comment on,” Buford said.

Re-signing Duncan to a Garnett-like deal, with the 2012-13 season starting somewhere in the $10 million range, would not get the Spurs under the salary cap.

But it would help accomplish the more feasible goal of moving them below the luxury tax threshold, set at $70 million last season and expected to increase marginally for next season.

That is significant for reasons that go beyond owner Peter Holt’s pocketbook.

Only teams below the luxury tax have access to the full mid-level exception — expected to be worth a shade more than $5 million — with which to lure other free agents.

That won’t be enough for the Spurs to conjure a radical summertime makeover, but it might be enough to keep together the bulk of a team that finished 50-16 last season and advanced to the conference finals.

Other in-house free agents for the Spurs include forward Boris Diaw, who at age 30 could be chasing his last significant NBA payday, as well as restricted free agents Danny Green and Patrick Mills.

The Spurs have already extended qualifying offers to both guards — $2.7 million for Green, $1.08 million for Mills — giving the team the right to match other offers.

Knowing Duncan, he will likely give San Antonio the hometown discount, if he re-inks for a deal similar to what Garnett plans to sign in Boston, the Spurs first step this summer will be well done.

What do you think? How much should the Spurs offer Duncan, and for how long? Share your thoughts.

(Photo via sportige.com)