Guzan, 32, joined Boro from Aston Villa in July on a free transfer but has only played three times for the Premier League club so far as fellow summer signing Victor Valdes has settled into the No. 1 job.
The former Chivas USA keeper is said to be disappointed about his lack of action and is now reportedly exploring the option to return to the States when the January transfer window opens.
According to FourFourTwo, the 53-times capped US international is not necessarily looking for a Designated Player deal, giving him plenty of possible destinations should he indeed decide to head back across the Atlantic.
Both the LA Galaxy and New York City FC could be on the hunt for a new starting keeper during the MLS offseason, while the Illinois native’s hometown club Chicago Fire currently hold the top spot in the league’s allocation order.
Expansion sides Atlanta United and Minnesota United will move above the Fire before Guzan becomes available in January, however, and both teams remain without a certified No. 1 ahead of beginning MLS play next season.
Reports this week have suggested that Fire are set to trade first-choice stopper Sean Johnson to Atlanta, though, in a deal which would see Veljko Paunović’s side move back to the top of the order and open up their starting spot between the posts [h/t MLSSoccer.com].
As well as following in the footsteps of fellow USA keeper Tim Howard, who joined the Colorado Rapids from Everton in the summer after a 13-year spell in England, a move to MLS would see Guzan return to the league where he first made a name for himself as a professional.
After being drafted by Chivas USA with the second overall pick in the 2005 SuperDraft, the former University of South Carolina standout quickly established himself as one of the league’s top shot-stoppers, going on to make 79 regular season appearances for the now-defunct franchise over the next three-and-a-half years while also winning the 2007 Goalkeeper of the Year award.
His impressive form not only earned him a regular place in the USA squad as Howard's main backup but also attracted the attention of then-Villa manager Martin O’Neill, who eventually brought him to England in August 2008 after an earlier deal collapsed over work permit issues.