The team is expected to sign both Clark and Brown to 10-day contracts on Thursday so they can have them under contract for seven games, sources say.
Brown, a seven-year veteran, played 10 games with the Spurs this season but was released after the second of two 10-day contracts. He averaged 2.3 points and 1.2 rebounds, shooting 28 percent from the field. Last season, Brown averaged 10.5 points and pulled down 2.5 rebounds in 59 games for the Phoenix Suns.
Phoenix traded Brown to Washington in a deal centered around Marcin Gortat during the preseason. The Wizards waived Brown shortly after the trade was completed.
Sources told ESPN.com that the Knicks also brought in Dahntay Jones for a first-hand look this week to assess the 33-year-old's readiness for an immediate return to the NBA.
The 10-year veteran was released by the Bulls during training camp in October and has been trying to find a new team.
Information from ESPN.com's Marc Stein was used in this report.