Tim Duncan, who declared himself "a Spur for life" in March, reportedly has followed through on his intentions to remain in San Antonio. The 36-year-old franchise cornerstone has agreed to a three-year contract to return to the Spurs, Yahoo! Sports reported Tuesday. The website reported the contract is expected to be worth approximately $36 million, or in the same range of the deal that Kevin Garnett agreed to with the Boston Celtics last week.