The Union are on the lookout for a new coach after John Hackworth was sacked in June and Moyes has appeared as a possible candidate after being spotted at two consecutive matches.
Moyes - without a job since being sacked by United in April - was in attendance as New York Red Bulls beat the Union in Eastern Conference action on Saturday.
He was a noticeable onlooker during Seattle Sounders' US Open Cup final success against Philadelphia on Tuesday.
However, Union CEO Nick Sakiewicz insisted Moyes' presence had nothing to do with the coaching job, which is being occupied by Jim Curtin on an interim basis.
"David Moyes is a friend and colleague of a number of us within our club and he was visiting our youth academy and club setup on his way to another location in the US," Sakiewicz stated.
"We played Everton FC in 2011 at PPL Park and since then we've had a friendship with David.
"He is an outstanding individual and we are honoured to know him and have an ongoing relationship."