As a senior in 1991, he was named Gatorade's Nevada State Baseball Player of the Year and finished with a 0.79 earned run average and 141 strikeouts in 61.2 innings pitched.

[1] Estes initially committed to play college baseball at Stanford University but instead signed with the Seattle Mariners after being selected in the first round of the 1991 MLB Draft.

Estes made his Major League debut with the Giants on September 16, 1995, working 5.1 innings as a starter against the Pittsburgh Pirates.

Estes would hit a two-run homer off Clemens in the fifth inning of the eventual 8-0 Mets win, setting off a loud roar from the sellout crowd of 54,347 and derisive chants of "Ro-ger!

Estes would ultimately start 23 games for the Mets, with a record of 4-9 and a 4.55 ERA, before he was traded again on August 15 to the Cincinnati Reds for Brady Clark, Raul González, Elvin Andújar and Pedro Feliciano.

[11] Estes began his 2007 comeback with minor league appearances in Single-A, though he was soon promoted to Triple-A Portland.

On January 9, 2009, Estes signed a one-year minor league deal with the Los Angeles Dodgers with an invitation to spring training.

[12] He was expected to compete for the fifth starter position but pitched poorly in spring training games and was released on March 22.

[13] However, after thinking about his options, he decided to stay with the Dodgers and report to minor league camp to attempt to transition into a situational reliever[14] The Dodgers assigned Estes to the AAA Albuquerque Isotopes to open the season, where he was 3–4 with a 3.08 ERA in 13 starts before announcing his retirement because he did not want to pitch in AAA.

[16] Estes and Aurilia serve as co-hosts of Giants pregame and postgame shows on NBC Sports Bay Area.

He is also an occasional fill-in analyst on Giants road game broadcasts, working alongside Duane Kuiper and Dave Flemming.

Estes previously did television color commentary for the Reno Aces of the Pacific Coast League.