FC Dallas defender George John has enjoyed a breakout season for the Western Conference champions, and his play has caught the attention of clubs in Europe, with one stepping up with a considerable offer.

Sources tell FOX Soccer that English club Blackburn has made a considerable offer for John, though the exact figure remains unknown. MLS and FC Dallas are considering the offer and could sell John before the close of the European transfer window.

Drafted in 2009 out of the University of Washington, John has quickly emerged as one of the best and most consistent centerbacks in MLS, with his aerial prowess and strength, he has been a key factor in Dallas' emergence as a Western Conference power in recent years.

Selling John would secure a financial boon for FC Dallas, which could lose John to free agency after the 2012 season. Selling him now would allow the club, and MLS, to secure a sizable transfer.

FC Dallas is currently in second place in the West and a strong MLS Cup contender, but losing John could hurt the team's chances of returning to the MLS Cup Final. Dallas does have defensive depth, but does not boast another centerback nearly as dominant as John to partner with the strong and steady Ugo Ihemelu.

John's stellar form for MLS recently led to interest from the Greek national team, which he is eligible for. As a Greek citizen, John can play for Blackburn as soon as he secures a Greek passport and will not have to go through the UK work permit process that has often slowed the ability of some American players to make moves to England.

If he does go to Blackburn, John would join another MLS alumnus, former DC United defender and Blackburn captain Ryan Nelsen, who joined Rovers after the 2004 season.