[1] He played in MLB for 13 seasons as a catcher for the Milwaukee Brewers, Toronto Blue Jays, St. Louis Cardinals, and San Francisco Giants.

From Reynoldsburg, Ohio, Matheny was selected by the Brewers in the eighth round of the 1991 MLB draft from the University of Michigan (UM).

In 2012, the Cardinals were wild card winners, and from 2013–15, claimed three consecutive NL Central titles, including winning a career-best 100 games for Matheny in 2015.

[6] Two days before he was due to attend his first class at Michigan, Blue Jays general manager Pat Gillick appeared at Matheny's home to convince him to sign.

Remaining upright, Matheny placed his hand on his hip as Pirates catcher Jason Kendall and home plate umpire Jerry Crawford motioned wildly for the Brewers trainers.

Matheny barely made the Cardinals roster after the spring training session, but went on to earn the starting catcher's role in the 2000 season.

[18] Matheny helped the Cardinals improve from their fourth-place finish in 1999 to capturing the National League Central Division title, and claimed his first Gold Glove award in the process.

[17] After teammate Darryl Kile's sudden death in the summer of 2002, Matheny showed that he was "an inspirational leader", helping the team to cope and make it to the National League Championship Series.

After the 2003 season, the St. Louis and Houston chapters of the BBWAA voted for Matheny as the inaugural winner of an award established in Kile's honor.

His defensive contributions helped St. Louis reach the postseason in four of his five years with the team, including claiming the National League pennant in 2004.

[21] He became a free agent after the 2004 World Series, primarily due to the emergence of rookie catcher Yadier Molina, with whom he would eventually be reunited.

Matheny continued his defensive excellence, compiling a team-record .999 fielding percentage and leading National League catchers with 13 double plays, 77 assists, and 39 base-stealers caught stealing, earning his fourth Gold Glove.

[13][5] He also took home the Willie Mac Award that year, accorded annually to a San Francisco Giant for spirit and leadership.

MLB.com's Giants beat writer, Rich Draper, articulated that Matheny's career was likely over due to continued struggles with post-concussion syndrome.

[24] On February 1, 2007, Matheny announced his retirement from Major League Baseball at the age of 35 due to ongoing symptoms of post-concussion syndrome.

[25] Shortly thereafter, Matheny became a baseball mentor for Protégé Sports and filming some catching tips and drills for the Scottsdale-based company.

[29] Twenty days later, Matheny was ejected from a game for the first time for arguing a pivotal safe/out call by umpire Bill Welke in the bottom of the 10th inning of a 3–2 loss to the Chicago Cubs.

However, in 2013, St. Louis lost four key players to season-ending injuries, including Chris Carpenter, Rafael Furcal, Jaime García and Jason Motte—rookies comprised half of the World Series pitching staff.

[43][44] With an 11–1 win over the Pittsburgh Pirates on September 30, the Cardinals won 100 games for the first time in Matheny's managerial career, while clinching their third consecutive NL Central division title.

[50] On May 1, 2018, Matheny became the fourth person, after Red Schoendienst, Whitey Herzog, and Tony La Russa, to manage 1,000 Cardinals games.

[67] Matheny routinely chronicles his life experiences and maintains a blog of which topics includes leadership and changing the culture of youth sports.

[5] The field has a completely flat and firm rubber surface and other features to allow children with a wide array of physical and mental handicaps to participate.

In 2005, Matheny founded MPD Partnership with two former professional indoor soccer players, Daryl Doran and Brett Phillips.

After Doran left the partnership to start a gym, Matheny and Phillips used their money to secure an $11.8 million loan from the Business Bank of St. Louis for an 11-acre tract near Interstate 64.

[74] Matheny's attorney, Robert Blitz, was handling a similar case—Fischer and Frichtel, a homebuilder who also defaulted on assets after sustaining losses over the same time period, contends that they should not be fully liable for what is termed as "deflationary debt".