Maybe OB is playing a bit of mind games here and having Mann in the starting side until the last minute then bring Hoy in to 6.
After last weeks game OB said Mann's ankle had swollen up pretty quickly, hard to think he would be right to play or near 100% fit already. OB talks about resting players and the team needs to draw on the whole clubs roster not just the starting 17.
Now is a great time to rely on that depth and give Mann a rest, or play less minutes from the bench. Why play an underdone player against such a dangerous opponent.