I was curious about players who are still playing that once wore the Metro jersey. Luckily, we have a complete list of players who have played for us in MF.
Michael Bradley (2005) - Toronto FC, MLS, 30
Ricardo Clark (2003-2004) - Houston Dynamo, MLS, 35
Ramiro Corrales (1998-2000) - Santa Cruz Breakers FC, PDL, 41 (Player-Coach)
Danilo da Silva (2005) - Internacional, Brasileiro Série A, 31
Cornell Glenn (2003) - Central FC, Trinidad an Tobago Pro League, 37
Jason Hernandez (2005) - Toronto FC, MLS, 34
Tim Howard (1998-2003) - Colorado Rapids, MLS, 39
Joselito Vaca (2004) - Blooming, Bolivian Professional League, 35
Abbe Ibrahim (2005), 31
Still only 31, so he could definitely be playing. The last information I can find is that he was playing for CF Mounana in Gabon in 2012.