Philadelphia swoop for Colombian duo
The much-travelled Mondragon, 39, will join the MLS from Bundesliga club Cologne while Valdez is making his first overseas signing after playing his entire career in his homeland with America de Cali and most recently Santa Fe.
In addition to Germany, Mondragon has also played for club teams in France, Spain, Turkey and Argentina. He has made 50 appearances for Colombia and played at the 1998 World Cup.
Valdez, 25, has been capped four times by his country.
Colombian players have enjoyed some success in MLS. Last season's MVP was FC Dallas midfielder David Ferreira while the most prolific goalscorer of the past four years, Juan Pablo Angel moved to the Los Angeles Galaxy on Wednesday from New York Red Bulls.