Boeing737-800 (34706/2014) was originally leased by Air China from Icelease and wfu by the Chinese airline in May 2014 and returned to the lessor. It was registered to Transaero Airlines but they did not take up the lease.
If a Chinese airline gives up on an aircraft that is 8 years old and a Russian airline refuses the same aircraft after registration, then it’s anyone’s guess what might be wrong with it......or what would be needed to be spent on it....
JET2 would appear to have their fleet requirements ready now for summer 2015 and it would be a surprise if there was any further addition to the fleet.