Read the full letter below:
"In the midst of what felt like never ending adversity and failure, I was traded to the Chicago Cubs on July 2, 2013. This was the beginning of a four and a half year stretch that would forever change our lives. On the verge of walking away from the game I love dearly, Theo called, and the transformation began. I looked myself in the mirror, as well as my two year old son and pregnant wife knowing in my heart that everything was about to change.
"Chicago was our home, and will forever be a special place for my entire family. We raised our children in Wrigleyville, one of the most iconic places in all of sports. Going to work every day was an honor for many reasons from the storied history of the organization, to the high character individuals I was surrounded by year after year. Three consecutive NLCS appearances, two NL Central Titles, and a World Series Championship… the first in 108 years. Childhood dreams turned reality, thanks to so many amazing people, all holding one another to a very high standard.
"I send gracious thanks to the Ricketts family and front office for their commitment to winning at any cost. Going the extra mile to take care of our families was never taken for granted. I was lucky to have dedicated teammates that willingly shed blood, sweat, and tears to achieve our goals. I will miss going to battle with all of you, but look forward to competing on opposite sides moving forward. Lastly, thanks to all Cubs fans around the world for standing with us, and investing in us even when times were tough. You will all be missed dearly. Thanks for the memories.
The Cubs posted their own heartfelt message ealrier Monday thanking Arrieta and his wife Brittany.