England left with plenty to ponder after India series defeat
They will, however, have plenty of time to conduct a thorough review, with their side not in red-ball action again until facing the West Indies at Lord's in July.
AFP Sport looks at some of the key issues now confronting England in Test cricket:
'Refining' Bazball
If self-knowledge is the beginning of wisdom, McCullum's post-series acceptance England will have to "refine" their approach was a start on the road to recovery.
'Baz' McCullum and Stokes won 10 of their first 11 Tests in charge but have since lost seven of the last dozen.
Few disagree with the basic premises behind 'Bazball', an approach grounded on the idea of trying to free players from the fear of failure and taking the attack to the opposition.
But there were times when England appeared to get carried away with their own rhetoric, notably when star batsman Joe Root was dismissed off a high-risk reverse scoop during a third-Test collapse in Rajkot.
It was notable that when Root reverted to type scores of 122 not out, 11, 26 and 84 duly followed.
England might still have been beaten adopting a more nuanced approach -- it is now 12 years since India lost a Test series on home soil -- but it was still telling when former New Zealand captain McCullum said: "We will allow the dust and hurt to settle a bit and then use that to make changes we need to ensure we are a better version of what we have started out as.
"We will have some time to reflect and come back bigger, stronger and more refined."
100 and out for Bairstow?
Writing off Jonny Bairstow's Test career has often served only to inspire him to greater heights. But having now reached the landmark of 100 Test appearances, a feat all the more impressive given England have often appeared uncertain as to whether he should be their red-ball wicketkeeper or a specialist batsman, doubts about his five-day future have resurfaced.
The 34-year-old didn't once reach 40 during 10 Test innings in India, while Ben Foakes, a more skilled gloveman, impressed behind the stumps.
England do have a ready-made middle-order replacement for Bairstow, with Yorkshire team-mate Harry Brook waiting in the wings
England dropped Graham Thorpe after his 100th Test in 2005, with Kevin Pietersen given a Test debut in his place, and Bairstow may now suffer a similar fate.
In a spin
One of the successes of the tour for England came with the form of youthful spinners Tom Hartley and Shoaib Bashir who, despite being plucked from virtual obscurity, took 39 wickets between them.
But now there are concerns about what will happen to the pair when they return to England, where early season conditions often favour seamers over spinners.
That means counties can go into games with just the one slow bowler.
Bashir will be up against England colleague Jack Leach, if fit following knee surgery, at Somerset while Hartley will return to a Lancashire side who have just signed Australia off-spinner Nathan Lyon.
"It will be frustrating if they weren't given opportunities at county level," said McCullum.
"There's a very real possibility of that being the case but, without wanting to dictate to counties because they have their own agendas, I think you'd be slightly mad if you didn't give them more opportunities in county cricket."