The Dallas defender will undergo a physical with the Premier League squad on Wednesday after the Rovers coach confirmed the signing.
Blackburn Rovers coach Steven Kean confirmed that the club has reached an agreement with FC Dallas for the American defender on Tuesday. Goal.com reported earlier this week that the deal is worth around $3.2 million.
"We are told that it is moving smoothly so he will be here tomorrow to get his medical," Kean said.
John, 24, has enjoyed a breakout season this year, leading one of Major League Soccer's stingiest defenses, which ranks third in goals allowed. He now has the opportunity to help a Blackburn backline that recently lost Phil Jones to Manchester United.
"We have always been looking for a replacement for Phil Jones and George John is a very imposing figure and we think he can fill the void left by Phil," Keane said. "It is a very big void and big boots to fill."
FC Dallas president Doug Quinn said in a statement Monday that John was on his way to Greece to take care of passport issues prior to finalizing the deal.
It is believed that Dallas did not want to sell George, but a source indicated to Goal.com that money played a factor as the small-market MLS team has struggled with attendance numbers.
The move will likely increase the recruitment of George on the international level. He is eligible to play for both the United States and Greece and could be called up by either nation for upcoming matches in September.