Complex sentence: Ironically, although England may have used substitute fielders to rest bowlers between spells, this appearance by Pratt was not among them: he was replacing Simon Jones, who had been taken to hospital with an ankle injury.
Split into simpler sentences: Ironically, although England may have used substitute fielders to rest bowlers between spells, this appearance by Pratt was not among them. He was on for Simon Jones, who had been taken to hospital with an ankle injury.