Michael Turner 2009. Sold dirt cheap to a rival because the then chairman needed cash, and was replaced with inferior players. Relegation inevitably ensued.
Arguable whether it was greatness per se when I recall him being a back up, but Roy Carroll played enough to get a Premier League winners medal after leaving us
He was great for us, but did he do anything special afterwards? Certainly didn't hit the heights most City fans expected him to.
Sold for £4 million, not the £6 million reported at the time. He went on to make over 100 appearances in 5 seasons in the PL for SAFC & NCFC, unlike nearly all his City team mates . Injury-plagued, our defence was never the same, but the chairman got his liquidity.