But Sky Sports News understands the deal to move to the U.S. capital was drafted over the past seven weeks with DC United's chief executive Jason Levein, who also part-owns Swansea, during several visits by Stretford to the US.
When first asked about the deal, Olson told reporters in the U.S.: "I don't know what you're talking about".
According to Sky Sources, it is understood Rooney has played his last game for Everton after saying his goodbyes on Saturday to staff and players.
Allardyce said yesterday that Rooney has not requested to leave the Merseyside club but he would be "comfortable" if the forward wanted to move on.
"Only after I've spoken to him today will I find out where the situation actually lies".
"So, I've got to say, if he chooses to go, DC will be getting a good player".
Everton's final game of the season will come against West Ham United at the London Stadium on Sunday.
Allardyce muttered darkly about not being able to play him alongside Gylfi Sigurdsson, Everton's other marquee summer signing, while at the same time complaining that Rooney did not get into the box enough.
Rooney, Everton's leading goalscorer this season, has become increasingly frustrated with a reduced role under Allardyce. "We've not been in any hard situations since the time I've been here because we're two adults and we talk".
One year on, it may be even more hard to succeed. Then he is in the Premier League again with Everton, so I think his career in England was ideal. That's it. Next season is already planned.
"I think recruitment is the start of the process to try and achieve a top six challenge".
"You would need at least two players to be at the 15 mark and you need the midfielders and wide players to be in the sevens to tens".