The new Chelsea signing was reportedly offered to the Tyne-Wear rivals.
But the 26-year-old later ended up at Chelsea after a £4 million move.
The Black Cats' decision is a surprise considering their need for defensive reinforcements - but Newcastle are said to consider their back line strong enough to cope without him.
Now, of course, he is with the Premier League champions and will likely be called upon to aid his side's current defensive struggles.
Considering Chelsea's transfer history, any signing they deem good enough would surely be equally acceptable for the likes of Sunderland and Newcastle. Clearly, though, both clubs disagreed.
The main question at the end of the day, then, is whether Sunderland and Newcastle showed bad judgement - or whether Chelsea did in their desperation at not signing John Stones...
The Blues also recruited 23-year-old Reading centre-back Michael Hector on Deadline Day, while the Tyne-Wear rivals both experienced relatively quiet days of their own.