San Antonio Spurs center Tim Duncan recorded the 15,000th rebound of his career during Thursday's 109-101 win over the Chicago Bulls, becoming just the sixth player in NBA history to achieve the milestone, per NBA on Twitter.

The 39-year-old big man otherwise had an unassuming night, finishing with just seven points, three boards, four assists and two steals in 28 minutes, making three of his seven field-goal attempts and one of his three free throws.

Duncan's current averages of 8.5 points, 7.4 rebounds and 25.2 minutes are by far the lowest of his career in each category, yet his Spurs own their best-ever record (55-10) through 65 games, with forwards Kawhi Leonard and LaMarcus Aldridge picking up all of the slack and then some.

Of course, Duncan is still a solid contributor on a per-minute basis, and his reduced statistical output is largely the product of a concerted effort to keep him in tip-top shape for the postseason.

With San Antonio very likely to end up as the No. 2 seed in the Western Conference, we'll probably see Duncan rested more than usual over the final 17 games of the season, unless the Spurs can somehow manage to gain ground on the top-seeded Golden State Warriors (57-6).

Granted, San Antonio does still have three games remaining against the Warriors, but two of those don't take place until the final week of the season.