Valent was an All-American at Canyon High School in Anaheim, California . On June 1, 1995, he was drafted in the 26th round of the amateur draft by the Detroit Tigers, but he did not sign and instead elected to attend college at UCLA.
He had a standout career at UCLA alongside teammates Troy Glaus, Eric Byrnes, Chase Utley, and Garrett Atkins. He helped lead UCLA to the college world series in 1997.
Valent has the most career home runs in Pac-10 history with 69, and is the UCLA career RBI (219), in only three years of play.
He was the Pac-10 Player of the year in 1998. On June 2, 1998, Valent was selected in the first round of the supplemental draft by the Philadelphia Phillies (42nd overall).
Of his collegiate career, Valent perhaps prophetically said:
"College baseball was fun, but it's a little deceiving because of the aluminum bats. If you hit home runs in college, you aren't necessarily going to hit them as a professional."
In his brief playing career, he provided good power from the left side of the plate. A solid pinch-hitter and valuable utility man; he was a competent first baseman who could play either left or right field effectively.
On August 31, 2003, Valent was traded to the Cincinnati Reds for catcher Kelly Stinnett.
On December 15, Valent was drafted by the New York Mets in the Rule 5 draft.
Most of Valent's playing time was with the Mets. On July 29, 2004, Valent became the eighth player in Mets history to hit for the cycle in a game against the Montreal Expos. In late August, he had three pinch-hit home runs. With the Mets, Valent wore uniform number 57 (later worn by pitcher Johan Santana).
On January 12, 2006, Valent was signed as a free agent by the San Diego Padres, but was released on May 14 after playing in 30 games for their Triple-A farm club, the Portland Beavers.
In a four-season career, Valent was a .234 hitter with 13 home runs and 36 RBI in 205 games.
After being released from the Padres organization, Valent signed a one-year contract worth 50 million Yen to play right field for the Tohoku Rakuten Golden Eagles in Japan's Pacific League.
In December 2008, Valent was named the hitting coach for the Single-A Williamsport Crosscutters of the Philadelphia Phillies organization, but was reassigned to a scouting position in January 2009.