Valeri started his professional career with his hometown club Lanús in 2003. He made his debut for Lanús under the direction of Miguel Ángel Brindisi on 27 September 2003 in a 1–1 draw with Vélez Sarsfield. In 2007, he was part of the squad that won the 2007 Apertura tournament, Lanús' first ever top-flight league title.
Loan spells and return
On 16 July2009, Valeri was loaned to Portuguese champion FC Porto, where he played one season, winning the Portuguese Cup. Porto also won the one-match 2009 Portuguese Super Cup, though Valeri did not play. He then spent six months on loan at Spanish club UD Almería. In 2011, Valeri rejoined Lanús and captained the team in its runner-up campaign in the 2011 Clausura.
Portland Timbers (2013–present)
In January 2013, Valeri was loaned to the Portland Timbers of Major League Soccer on a contract paying $400,000 annually. Portland exercised its option to acquire Valeri on 6 August 2013. Valeri helped Portland top the table in the Western Conference that year. On 6 August 2014 Valeri was part of the Major League Soccer All-Star Team, which won against German Bundesliga title winner and recent European Champions League winnerBayern Munich. Valeri assisted on the game-winning goal. In May 2015, Valeri returned to the field as a substitute in a match after recovery from a serious injury suffered at the end of the previous season. On 6 December 2015, Valeri scored in the MLS Cup Final at the 27 second mark after Columbus Crew goalkeeper Steve Clark was outsmarted from his defender's back-pass under pressure from Valeri; it was the fastest goal in MLS Cup history. His decisive performance in Portland's 2-1 victory led to his winning the MLS Cup MVP Award. On 10 August 2016, the Portland Timbers announced the signing of Valeri to a three-year extension, keeping him in Portland through the 2019 MLS season. Valeri had a standout season in 2017. In August, he became the eighteenth player in league history to have scored at least 50 goals and 50 assists. He broke MLS records for consecutive matches with a goal and most goals scored by a midfielder in the regular season. He was also the second player ever to score 20+ goals and 10+ assists in the regular season, after Sebastian Giovinco in 2015. He was considered instrumental in helping Portland to a first-place finish in the 2017 Western Conference title race. On 4 December, Valeri was awarded the Landon Donovan MLS MVP Award as the league's most valuable player during the 2017 regular season.
International career
Valeri played his first game for Argentina on 16 March 2011 in a friendly match against Venezuela, helping Argentina win 4–1. He played two further matches for Argentina that year. It sparked some controversy when Diego was not considered for Argentina, after winning the MLS MVP Award.
Style of play
A technically gifted and creative player, Valeri is known for his skill and ability to provide assists for teammates, and usually plays as an attacking midfielder. Although he usually serves as a playmaker for his teams, he is also capable of scoring goals himself. Diego Valeri is dangerous outside the box, and is a good header of ball, as shown by some of the goals he scored with his head during the 2017 season.
Personal life
Valeri holds a U.S. green card which qualifies him as a domestic player for MLS roster purposes.
