Spencer stepped down from his role as Dynamo number two under Dom Kinnear and reports suggest he is set to take the reins at Portland when the club enters MLS in 2011.
Wilkinson, a New Zealand native who has been with Portland as a player and coach since 2001, said that Spencer was certainly somebody the expansion franchise is set to target.
"He is still a person of interest for us. We'll continue talking and see where it takes us," said Wilkinson. "But John has got a lot of options."
Spencer cited personal reasons to step down from the Dynamo, the club he helped win the MLS Cup in 2006 and 2007.