He was also voted Florida's Player of the Year, was a USA Today All-USA selection, and was rated by Baseball America as the best defensive high school shortstop in the country.

The Diamondbacks sent first baseman Erubiel Durazo to the Oakland Athletics, who, in turn, sent minor league pitcher Jason Arnold to the Blue Jays.

López was traded by the Reds on July 13, 2006, to the Washington Nationals along with Austin Kearns and Ryan Wagner for Gary Majewski, Bill Bray, Royce Clayton, Brendan Harris, and Daryl Thompson, a minor league prospect.

This switch was due to the recovery of the Nationals original shortstop, Christian Guzman, who had injured himself in 2005, though he later gave the position back to Lopez after sustaining yet another injury during the 2007 season.

On April 24, 2008, López hit a grand slam to give Washington a 7–3 lead en route to a 10–5 victory over the Mets.

[3] Lopez hit two home runs in his first two at-bats in his first game with the Diamondbacks, which is the first time that has happened since Richie Sexson in 2005 with the Seattle Mariners.

On July 19, the Milwaukee Brewers acquired López in exchange for minor league outfielder Cole Gillespie and pitcher Roque Mercedes.

On September 21, 2010, López was released by the St. Louis Cardinals because he wasn't fitting in with the team's focus on younger players.

On February 2, 2011, López signed a minor league deal with the Tampa Bay Rays with an invite to spring training.