Daye, 25, spent last season with both the Memphis Grizzlies and Detroit Pistons, averaging 4.5 PPG over 55 games with a .433 field goal percentage. The Knicks watched Douby in late June, according to Matt Sugam of SNY Rutgers.
Morris, 22, played 48 games for the L.A. Lakers last season, in which he averaged 4.0 PPG and had a .388 field goal percentage.
Douby, 29, has not played in the NBA since he played just seven games for the Toronto Raptors in 2008.
The Knicks also worked out Bobby Brown, as reported earlier.