Third-year pro Brooks Bollinger will still get the start on Sunday when the Jets head to Baltimore to face the Ravens.
The Jets announced Tuesday that quarterback Chad Pennington suffered a torn rotator cuff in Sunday's 26-20 overtime loss to the Jacksonville Jaguars and will likely be lost for the year.
Backup Jay Fiedler suffered a dislocated right shoulder on Sunday and also could be lost for the year.
Testaverde played for the Jets from 1998-2003. In his first year with New York, he completed 259-of-421 passes for 3,256 yards with 29 touchdowns and seven interceptions in 14 games.
Testaverde played in all 16 games for Dallas last season and completed 297-of-495 passes for 3,523 yards with 17 touchdowns and 20 interceptions.
Testaverde has thrown for 44,475 yards with 268 touchdowns and 255 picks in his 18-year career.