No idea if he had a trial or not, but it appears that he is currently suiting up for his club (Metapan) of the Salvadorian premier division which is now three games young on the campaign. He would therefore have to transfer to the Revs as opposed to joining on a free. This means, among other things, that the deal would have to take place rather shortly due to the FIFA transfer window if Reyes-to-the-Revs was indeed a reality. Dollars to donuts that Nicol has other plans.
In my opinion it is unlikely for a few reasons (keep in mind that I've been wrong many times before on such matters, though, so take it as you wish): 1) Central American clubs historically ask for far too much money on contract transfers to MLS, so I wouldn't be surprised if Metapan charges a hefty premium for the guy that they consider the top striker on the team (that was runner-up in 2005) when they've already started their season. 2) We all know that Steve Nicol likes tough, physical, hard working players with tactical sensibility. I've seen Reyes a few times and while having some good characteristics himself, those that he has are far from tough, physical or tactical. He's good, but i wouldn't describe hm as a SN type of player by any stretch. 3) He's not exactly young at 30 years old, so a move that includes a transfer fee on a striker who has unproven production at a high level and who has only a few years left is less likely. Carlos ruiz came up as a kid and the league got a bargain with him. There are others more in this line if the league is looking for Central American strikers.