Rooney has been given permission to sit out the trip as wife Coleen is due to give birth to the couple's second child.
The 27-year-old's Old Trafford future is in doubt after he asked for a transfer recently.
Sir Alex Ferguson has now passed that matter on to new manager David Moyes to deal with.
However, after being left out of Ferguson's final home game before retirement last week, Press Association Sport understands Rooney will also miss the Scot's final one ever as a manager at The Hawthorns on Sunday afternoon.
Rooney has asked to leave Manchester United this summer even though he still has two years on his contract remaining.
Ferguson revealed last week the request had been turned down, and, along with Gary Neville, advised the England forward to get away during the summer, get his head sorted out and return refreshed.
The matter is not quite so simple, as United will not want to allow the 27-year-old to drift beyond the summer without some kind of clear vision of his future.
However, as Ferguson acknowledged, it is not his problem any more.
"I'm no longer interested in that," said the Scot.
"Quite rightly, David is going to deal with it. I am happy with that."
United look set, however, to confirm the future of defender Rio Ferdinand early next week.
It is understood negotiations over a new deal are at an advanced stage and provided there are no unforeseen hitches, an official announcement will be made.