 Colo Colo finished Runners-Up in the Chilean Apertura National Championship that year and also played in the 2003 Copa Libertadores.Walker came back to the US later that year, signing with the MetroStars, after starting goalkeeper Tim Howard signed with Manchester United.In 2003 with the MetroStars, Walker became the third goalkeeper in MLS history to finish a season with sub-1.00 Goals Against Average (GAA), capturing the league-best 0.95 GAA.