Well if you missed the Spurs as they played Philadelphia and New York during their last road trip, you may be unaware that Anthony Lamb was even a member of the San Antonio Spurs.
As the Spurs were hit with the recent COVID health and safety protocols (at one point or another Dejounte Murray, Derrick White, Doug McDermott, Tre Jones, Lonnie Walker IV, Thaddeus Young, Devin Vassell, and Keldon Johnson were all unavailable due to the coronavirus league rules), the Spurs grabbed a handful of players on emergency 10-day contracts.
Anthony Lamb was signed with the Spurs January 6th on one such contract.