Not sure it is relevant, but Barnes was lights out from April to June when the spin rate on the 4 seamer was around 2400 plus,
But by July it was down to around 2100 plus.
I see two things:
1.) Barnes got over used and his arm went dead.
2.) Barnes sustained an injury and kept his mouth shut.
Whatever happened is unknown, but we should know fairly early in the season how he is throwing.