Former U.S., Chicago Fire teammates Chris Rolfe, Justin Mapp both retire

Former U.S. internationals and Chicago Fire teammates Chris Rolfe and Justin Mapp both took to social media to express gratitude to fans, teammates and family in announcing their respective retirements on Thursday.

Neither Rolfe, 34, nor Mapp, 33, played in 2017, with the former having been sidelined since April of 2016 after sustaining a concussion while playing for D.C. United and the latter sidelined by injuries after making just six appearances for Sporting Kansas City in 2016.

The two spent five seasons together in Chicago from 2005 to 2009, combining for 297 appearances for the club and accounting for 50 goals between them.

Mapp, who spent his entire career in Major League Soccer, won two U.S. Open Cups and a Supporters' Shield with the Fire early in his career before being drafted by the Montreal Impact in the 2011 expansion draft. He was part of two Canadian Championship teams in Montreal, where he played from 2012-2015.

Mapp also made eight appearances for the U.S. national team and was part of the 2007 team that won the Gold Cup.

Rolfe also spent most of his career in MLS, although he did play two seasons in the Danish top flight withAaB Fodbold from 2010-2012.

The Kettering, Ohio, native made 10 appearances for the U.S. and was enjoying a resurgence with D.C. United before sustaining a concussion that ultimately ended his career.

Rolfe is still battling the effects of the concussion and told theWashington Post:: "If I put it in a positive light, it's a lot easier to cope and believe things are going to get better.

"And if they don't, I am going to be okay. I'll be able to figure it out. I am strong enough. I will find things that bring me happiness and joy outside of things I can't do anymore."