Upton, 24, earned his second All-Star appearance in 2011, hitting .289 with 39 doubles, 31 homers and 88 RBIs while playing in a career-high 159 games.
Kennedy put together a 21-4 record with a 2.88 ERA in 33 starts, establishing himself as the ace of the Arizona staff.
The 26-year-old came up big in key games, as he compiled a 10-0 record against National League West opponents.
Roberts, meanwhile, nearly did not make the club out of Spring Training despite leading all of baseball with a .519 batting average and a .609 on-base percentage. Only a knee injury to Geoff Blum cleared the way for him to make the roster.
Roberts made the most of the opportunity, hitting .249 with 19 homers and 65 RBIs.
So far this winter, Gibson has already been named The Sporting News National League Manager of the Year, and he figures to win the same award from the Baseball Writers' Association of America.
In his first full season as manager, Gibson led the D-backs to a 94-68 record and the 2011 NL West title. That came on the heels of back-to-back last place finishes from the D-backs, who lost 97 games in 2010.
Upton and right-hander Daniel Hudson recently captured Silver Slugger Awards presented by Louisville Slugger, while left fielder Gerardo Parra received his first career Rawlings Gold Glove Award.
Hudson led all Major League pitchers in hitting with a .277 average. He stroked three doubles and a homer, drove in 14 runs and was especially tough with runners in scoring position, hitting .389. He became the second D-backs pitcher to win the award, joining Micah Owings in 2007.
Upton was also named to The Sporting News All-Star Team.
The local chapter of the BBWAA chose Upton as the team's MVP, while Kennedy was named Most Valuable Pitcher. The other award winners were Josh Collmenter (Rookie of the Year) and Miguel Montero (Good Guy Award).
While Kennedy and Upton had outstanding years, they will likely come up short in a pair of national BBWAA awards.
Kennedy will likely finish behind Dodgers lefty Clayton Kershaw and possibly the Phillies' Cliff Lee and Roy Halladay in the NL Cy Young Award voting.
The same fate will likely befall Upton in the race for Most Valuable Player. He faces stiff competition in the race from the Brewers duo of Ryan Braun and Prince Fielder, as well as Dodgers outfielder Matt Kemp.
In awards handed out by the team, slugging first baseman Paul Goldschmidt was named Organizational Player of the Year, while left-hander Tyler Skaggs garnered the Organizational Pitcher of the Year honor.