Don't have any insider info, but the writing should be on the wall regarding their next hire. Stop hiring coaches for the sole reason that they were able to run fast from the day they were born. Someone that has natural gifts far exceeding the norm can rarely explain those gifts effectively. This is true in all fields, as the most brilliant mathematicians make for horrible teachers to those that are much less gifted.
More often than not elite athletes like to tell themselves they had to work super hard to achieve their success, which in part is absolutely true, but it's often a case of succeeding despite the training they did rather than because of it. Additionally, elite athletes turned coaches have body control that they often can not teach to their athletes because it's so difficult to teach a sensation to someone who has never experienced it.
If Sheffield hires another former world class athlete that somehow makes the program tank even further he's got to start seriously worrying about his own job if he's not already.