Clark is the official team mascot of Major League Baseball's Chicago Cubs.
 He was announced on January 13, 2014 as the first official mascot in the modern history of the Cubs franchise.
 He was introduced that day at the Advocate Illinois Masonic Medical Center's pediatric developmental center along with some of the Cubs' top prospects such as number one draft pick Kris Bryant and Albert Almora, Jorge Soler, Mike Olt and Eric Jokisch.
 Over a dozen Cubs prospects were attending the Cubs' Rookie Development Program that week.
 The Cubs become the 27th team in Major League Baseball to have a mascot, leaving the Los Angeles Angels, Los Angeles Dodgers and New York Yankees as the remaining franchises without mascots.
 According to the Cubs' press release, Clark is a response to fan demands (expressed via surveys and interviews) for more kid-friendly elements at Wrigley Field Cubs games to keep pace with games in other cities that have more to offer youth fans.
Michael George Olt (born August 27, 1988) is an American professional baseball third baseman in the Boston Red Sox organization.
 He played college baseball at the University of Connecticut, and made his Major League Baseball (MLB) debut with the Texas Rangers in 2012.
 He has also played in MLB for the Chicago Cubs and Chicago White Sox.
Charles William Smith (September 15, 1937 – November 29, 1994) was an American professional baseball third baseman.
 He played 10 seasons in Major League Baseball (MLB) from 1960 to 1969 for the Los Angeles Dodgers, Philadelphia Phillies, Chicago White Sox, New York Mets, St. Louis Cardinals, New York Yankees, and Chicago Cubs.
Luis Adan Valbuena (born November 30, 1985) is a Venezuelan professional baseball third baseman for the Los Angeles Angels of Major League Baseball.
 He previously played for the Seattle Mariners, Cleveland Indians, Chicago Cubs, and Houston Astros.
 While primarily a third baseman, Valbuena has also played second base and first base.
Vladimir Guerrero Ramos Jr. (born March 16, 1999) is a Canadian-born Dominican professional baseball third baseman in the Toronto Blue Jays organization.
 He is considered the top prospect in the Blue Jays organization by both Major League Baseball (MLB) and "Baseball America".
 MLB ranks Guerrero as the 3rd best prospect in professional baseball, while "Baseball America" ranks him 2nd.
Joshua Adam Donaldson (born December 8, 1985) is an American professional baseball third baseman for the Toronto Blue Jays of Major League Baseball (MLB).
 He was initially drafted by the Chicago Cubs in the 2007 MLB Draft after playing for Auburn University during his time in college.
 Donaldson has also played for the Oakland Athletics, making his debut for the team in 2010, progressing with the team and eventually becoming an All-Star in the 2014 MLB season.
Kristopher Lee Bryant (born January 4, 1992) is an American professional baseball third baseman for the Chicago Cubs of Major League Baseball (MLB).
 Bryant attended the University of San Diego, where he played college baseball for the Toreros, and won the Dick Howser Trophy and Golden Spikes Award his junior year in 2013.
 The Cubs selected him number-two overall in the 2013 MLB draft and he quickly became one of the top prospects in baseball.
 Bryant made his major league debut in 2015 and won the National League Rookie of the Year Award.
 He won a World Series championship with the Cubs in , and was named the National League Most Valuable Player.
Todd Edward Zeile (born September 9, 1965) is an American former professional baseball third baseman and first baseman.
 He played sixteen seasons in Major League Baseball (MLB) from 1989 to 2004 for the St. Louis Cardinals, Chicago Cubs, Philadelphia Phillies, Baltimore Orioles, Los Angeles Dodgers, Florida Marlins, Texas Rangers, New York Mets, Colorado Rockies, New York Yankees, and Montreal Expos.
 He graduated from UCLA, where he played catcher.
 Only four players in MLB history have played for more teams.
Elmer Ellsworth Yoter (June 26, 1900 – July 26, 1966) was an American professional baseball third baseman.
 He played parts of four seasons in Major League Baseball from 1921 to 1928 for the Philadelphia Athletics, Cleveland Indians and Chicago Cubs.
Gary Thomas Scott (born August 22, 1968 in New Rochelle, New York), is a former Major League Baseball third baseman in 1991 and 1992.
 In each season, he was the Opening Day third baseman for the Chicago Cubs, but in each case he was back in the minor leagues within a few weeks.
 In 1991, he batted .165 until May 14, when the Cubs sent him down.
 On April 20, 1992 he was batting .103 when he managed to crack a grand slam at Wrigley Field.
 He was then sent down 3 games later.
 He was called up a few more times during that year but never reached the majors again.

Question: Clark is the mascot of the Chicago Cubs, introduced on the same day along with the teams top prospect an American professional baseball third baseman who attended what university?
Answer: University of San Diego