Let the team do it

The world is moving so fast now-a-days that the man who says it cannot be done is generally interrupted by someone else doing it.—Elbert Hubbard.

Transitioning to agile is hard, specially for managers who like having control. If your team says it can solve the problem with a viable solution and enthusiasm, let them do it. Most likely it will be done better than anything that is forced into the team. Never stop people from working hard by telling them it cannot be done, specially if they have a solution they want to try, it will only kill their motivation.

Even if it fails, the person will respect you for giving them a chance and in an agile environments that is time boxed failure is not catastrophic.