Goalkeeping coach Eric Steele will take charge of Aston Villa for their pre-season tour of Germany and Holland.
Aitken has seen his side beat Walsall, Hull and Wolves
Steele replaces caretaker boss Roy Aitken, who has withdrawn from the trip to continue his recovery from surgery.
"It's a step too far at this stage," said Aitken. "It's probably best that I leave it to people who are fully fit and able to work to full capacity."
Martin O'Neill has been strongly linked to the managerial post, vacant since David O'Leary left the club on 19 July.
Aitken, 47, is still recovering from surgery to remove a tumour following a routine medical check-up earlier in the summer.
Although the operation was a complete success, he has been advised to continue his rehabilitation under the guidance of his surgeon.
"When the manager left a couple of weeks ago, I was asked to take temporary charge and I came back to work earlier than I should have," added Aitken.
"The chairman Doug Ellis has been very fair and backs my decision to take a back seat for a few weeks and put my own health first."
Aitken joined Villa as O'Leary's assistant manager in 2003 and the club have won their three pre-season games under his stewardship, without conceding a goal.