NBA trade rumors: Spurs aggressively pursuing upgrade, according to report

The San Antonio Spurs sit atop the Western Conference, but that's not stopping them from aggressively trying to upgrade the roster, according to CBS Sports' Ken Berger.

The Spurs are 28-8 and currently hold a one-game lead over the Portland Trail Blazers and Oklahoma City Thunder in the West. However, San Antonio has struggled at times against the other teams currently in the West playoff picture, holding a pedestrian 7-6 record against those squads. The Spurs were also thumped on their home floor by the Indiana Pacers.

San Antonio hasn't often been known as a big player on the trade market, so some rival executives believe the organization realizes this season may be the final shot at a championship with the trio of Tim Duncan, Tony Parker and Manu Ginobili. Duncan is 37 years old and has a player option of $10.4 million next year. Parker is 31 and only has $3.5 million of his $12.5 million guaranteed for next year. Ginobili, 36, signed a two-year, $14.5 million deal this past offseason.

There are several areas where the Spurs could use an upgrade. With Tiago Splitter out around a month with a shoulder injury, another big man would be helpful, especially considering the struggles of Jeff Ayres. Another strong wing defender to go along with Kawhi Leonard would also be useful.