And amid reports that D.C. United will confirm his arrival on Thursday, Rooney posted an update on his Twitter page.
A picture on an aeroplane along with an emoji of the US flag suggests that a new chapter in a distinguished career is about to be opened.
United manager Jose Mourinho has already offered his support to a move, saying: "What next? He decides. MLS? In MLS you have always some iconic players who are going to end their career there. You have Gerrard, Lampard, Vieira, so many of them. Now you have Zlatan and Wayne. So I just hope he enjoys it.
"Of course he will bring the attention that MLS needs to attract more people to steal from the other sports that normally the American people are in love with."
Rooney is reportedly set to sign a two-and-a-half year contract worth £10 million ($13m) with D.C. United, making him the best paid player in the franchise's history.
The club are toiling at the bottom of the Eastern Conference in MLS, but Rooney's signing is expected to offer a boost ahead of the opening of their new Audi Field Stadium on July 14.
Rooney follows former England team-mates David Beckham, Frank Lampard, Steven Gerrard and Ashley Cole in making a move to MLS.