Seattle has been chasing Montero's rights for months, yet the former Deportivo Cali player has yet to sign an MLS deal, or any other deal, apparently. Montero scored 20 goals in 38 games for Cali in 2008.
Inquiries from Spanish club Real Betis haven't reached consummation, and questions about whether the 21-year-old Montero is a free agent or still under contract to Deportivo Cali have impaired negotiations.
Another source said Deportivo Cali is willing to cut another loan deal for Montero rather than sell his rights in a transfer.
A Seattle team executive stated several weeks ago he expected a deal to be done. Montero started his career in 2005 with Cali and has played on loan with Atletico Huila since 2006. He debuted for Colombia against Panama in 2007 in a friendly.
The Sounders will train Wednesday at the Virginia Mason Athletic Center in Renton, Wash., which is the headquarters and training complex for the NFL Seahawks.