Baker originally played football collegiately at Pennsylvania State University. Before the 2007 season, he was involved in two separate off-campus fights along with nine of his Penn State teammates. On June 26, 2007, Penn State temporarily expelled all ten involved players from July 1 through the end of the summer semester in mid-August. His expulsion was later made permanent. Baker transferred to Hampton University to continue playing football in 2008.
Professional career
Denver Broncos
Baker signed with the Denver Broncos on April 27, 2009. He played one game for the Broncos for the 2009 season. On September 3, 2010, the Broncos released Baker.
Miami Dolphins
On October 7, 2010, Baker was signed to the practice squad of the Miami Dolphins. He was promoted to the active 53-man roster on November 26, 2010. He played one game for the Dolphins in the 2010 season. The Dolphins released him on July 31, 2011.
Washington Redskins
On September 5, 2011, the Washington Redskins signed Baker to its practice squad. On December 6, 2011, Baker was promoted from the practice squad to the active 53-man roster. Without even playing a game for the Redskins, he was placed on injured reserve due to a quad injury on December 13, 2011. By the start of 2012 training camp, Baker was fully healed and was expected to compete with Chris Neild for the backup nose tackle position. After Neild was placed on injured reserve in the preseason, Baker made the final 53-man roster in his place. Originally set to become a restricted free agent, the Redskins tendered a restricted free-agent right-of-first-refusal qualifying offer to Baker on March 11, 2013. Baker officially accepted and signed the team's tender on April 10. He recorded his first career sack on Jay Cutler in the Week 7 win against the Chicago Bears. Set to become a restricted free agent again for the 2014 season, the Redskins announced they had re-signed Baker to a three-year deal worth $12 million, with $4 million guaranteed. He would switch from the starting left defensive end position to the nose tackle position after starter Barry Cofield was placed on short-term injured reserve. During a game against the Philadelphia Eagles on September 21, 2014, Baker hit Eagles quarterbackNick Foles following an interception by Foles. Foles was jogging towards the player who had intercepted his pass when Baker made a hard block on Foles. Following the hit, a brawl broke out on the sidelines between both teams. Baker was confronted by Eagles offensive tackleJason Peters with Baker clamping the face mask of Peters in retaliation and with Peters taking a swing at Baker which resulted in both players getting ejected in the scuffle. After the game, Baker responded to the incident saying, "I didn't even really hit him hard. I just hit him with my shoulder and he happened to fall. He's the quarterback and I guess that's why there was an ejection." Despite conflicting opinions on whether on the block was legal or not, he was fined $8,268 for the fight with Peters. On October 17, 2014, Baker was fined $10,000 for dragging down Cardinals quarterback Carson Palmer by the face mask during the Week 6 loss. Baker's gameplay in the 2015 surprisingly progressed so much that he beat out new free agent acquisition, Stephen Paea, for the starting left defensive end position. In the Week 4 win against the Eagles, he recorded two sacks on quarterback Sam Bradford, which was his first multi-sack game. At the end of the regular season, he recorded a new career-high of six sacks, which earned him the $280,000 bonus in his contract.
Tampa Bay Buccaneers
On March 9, 2017, Baker signed a three-year contract with the Tampa Bay Buccaneers. His contract was worth $15.75 million with $9 million guaranteed. In his lone season with the Buccaneers, Baker recorded 33 tackles and 0.5 sacks. On February 20, 2018, he was released by the Buccaneers after one season.
Cincinnati Bengals
On March 7, 2018, Baker signed a one-year contract with the Cincinnati Bengals. He was released on August 24, 2018.
Personal life
Baker has been childhood friends with nose tackle Terrance Knighton and Damik Scafe since high school, where the three of them were teammates. Knighton was Baker's best man in his wedding to ESPN talent producer, Jamila Phillips, on March 14, 2015. On January 7, 2016, Baker's first child, Aria, was born.
Legal issues
While attending Penn State, Baker was sentenced to two years of probation after pleading guilty two cases of assault on May 16, 2008.
