On February 13, 2014, Lawrie was announced as the cover athlete for the Canadian version of MLB 14: The Show. He replaces teammate Jose Bautista, who was the Canadian cover athlete for the previous two entries in the series. Lawrie hit his second career grand slam on April 15, 2014, in a 9–3 win over the Minnesota Twins. After the emergence of Juan Francisco as a viable option for the Blue Jays, Lawrie began playing second base against right-handed starting pitchers. He tied his career-high in home runs on June 6, 2014, when he hit his 11th of the season in a 3–1 win over the St. Louis Cardinals. Lawrie would then set a new career-high on June 20, when he hit his 12th of the season to assist the Blue Jays in a 14–9 win, having been down 8–0 after the second inning. Two days later, he was hit on the right hand by a pitch from Johnny Cueto and was forced out of the game. X-rays showed a fracture of his right index finger and he was placed on the 15-day disabled list. On August 5, Lawrie was activated from the DL and started at third base that night. In the 4th inning, he was removed from the game due to back tightness, and was placed back on the 15-day disabled list on August 7 with an oblique strain. On September 2, Lawrie was moved to the 60-day disabled list, ending his 2014 season. He finished the year appearing in just 70 games, and batting .247 with 12 home runs and 38 RBIs.
On November 28, 2014, Lawrie was traded to the Oakland Athletics, along with Kendall Graveman, Sean Nolin, and Franklin Barreto, for Josh Donaldson. After struggling early in the season, including a game on April 7 in which he struck out 4 times on 12 total pitches (earning him a golden sombrero), Lawrie hit his first home run as an Athletic on April 13. In a game on June 5 between the Athletics and the Boston Red Sox at Boston's Fenway Park, a fan named Tonya Carpenter was injured when Lawrie's bat broke while swinging at a pitch. The barrel of the bat was thrown into the stands, hitting Carpenter in the head. According to the Boston Police Department, Carpenter lost an extensive amount of blood and suffered life-threatening head injuries, but another fan wrapped her head in his shirt tourniquet and she was quickly treated and taken by Fenway Park medical personnel to Boston's Beth Israel Deaconess Medical Center.