The 41-year-old's contract expires in December and England's 19-12 defeat to France could have been Johnson's last in charge.
"The key thing from my point of view is that we take the next four to six weeks with Martin and review what has gone on," said Andrew.
"Martin will reflect on what has happened and why we have gone out in the quarter-final of a World Cup.
"It is very disappointing that it has happened. The important thing now is to take stock."