The Royals finished off the season 65-97, which tied them with the Indians for fourth in the AL Central. But in September, they went 15-13 to notch just their second above-.500 month of the year. The only other one was April, when they finished 12-10.
In the midst of their September, Butler went 37-for-102 with six homers, 26 RBIs, 10 doubles and a triple. He also posted a .459 on-base percentage and a .675 slugging percentage.
On Sept. 9, the 23-year-old collected three doubles in the Royals' 5-1 win over the Tigers. That gave him four three-double games this year, which was the most in a season in Major League history since 1900.
Another notable game came on Sept. 25, when Butler went 4-for-5 with two home runs and drove in the only four runs in a 9-4 loss to the Twins.
"I'm just trying to square the ball up and help the team win," Butler said when asked that night if he thinks about his numbers. "I just got pitches to [work with] tonight -- even on my last at-bat, I had pitches to get the job done before I struck out."
Butler finished the season with career highs in every offensive category and led the Royals in hits (183), doubles (51), walks (58), RBIs (93), batting average (.301), slugging percentage (.492) and on-base percentage (.362).
When Butler notched his 50th double of the season on Sept. 26, he became just the fifth player in Major League history to compile at least 20 home runs -- he finished with 21 homers -- and 50 doubles in a season before age 24.
The runner-up for AL Player of the Month was Twins outfielder Michael Cuddyer, whose eight home runs in September were tied for the most in the AL.
Alden Gonzalez is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.