The Rapids lost the first leg of the Scotiabank CONCACAF Champions League round of 16 match to Toronto FC, but the future looks bright for the 2018 season.
Hairston, who will be attending his first MNT camp, will report on January 10 to the National Training Center in Carson, California.
The Colorado Rapids will face a stiff test in their home opener in 2018, hosting the No. 3 finishers in last season's Supporters' Shield standings.
The Colorado Rapids signed Anthony Hudson to a three-year deal to take over as manager. Hudson, 36, joins Major League Soccer after guiding the New Zealand national team.
The Rapids exercised contract options on three players, including Jared Watts, and declined options on six players.
Blomberg becomes the Rapids’ first offseason signing and will occupy an international roster spot in 2018.
Two players were ejected in Seattle as the Rapids and Sounders played out the final game of the MLS regular season.
Colorado was playing the role of spoiler against their top rival in the final home game of the 2017 season.
In the midst of a lost season, Dominique Badji and Stefan Aigner provide hope for the future.
German winger Stefan Aigner tallied his second goal in as many matches to give the Rapids the early lead in a 1-1 draw Saturday.