If Ben Foakes is even considered to be dropped then there's something going fundamentally wrong. He walked into the side relatively unprepared (he'd just embarked on a six-month break from the game) and immediately looked like a man who'll play 80 Tests.
It does create a headache for the England selectors, but it's one they should be capable of dealing with. Let's look at the team as it stands.
1. Rory Burns (will get a full series to give him time)
2. Keaton Jennings (has just bought himself another 15 Tests)
3. A cry for help
4. Joe Root (the captain has decided to bat at four)
5. Ben Stokes (seems thoroughly unlikely he'll be left out)
6. Jos Buttler (vice captain and in-form batsman)
7. Ben Foakes (undroppable keeper-batsman)
8. Moeen Ali (pencilled in, depends on batting order)
9. Sam Curran (left-arm variety, three-dimentional cricketer)
10. Jack Leach (controlled spinner, bowls long spells)
11. Jimmy Anderson (still top-class, keep him until his arm falls off)
That glut of middle-order batsmen means there's a bowling deficiency. Moeen definitely plays, it's just a case of whether he bats at three or eight (yes, things are that silly). Of the two options, I would lean towards eight.
Then there needs to be a second new-ball bowler: the left-arm variety of Curran seems to be preferred currently. And a second spinner: I think Leach looked in control, where as Rashid looked one long-hop away from full-yippage.
So that leaves the number three slot. If Jonny Bairstow is going to slot straight back in with all his technical frailties forgiven, he has to bat three and not keep. If he's not prepared to do that then I think Joe Denly has to come in despite his best efforts to play himself out of the side. Or, and don't hate me for this, you charter a flight for Ian Bell.
The selectors talk of Foakes creating a "good headache" but the lack of a good number three under the age of 35 is more of a migraine.
* * *
In focussing their team on their traditional strengths, Sri Lanka have neglected their opponents' weaknesses.
Take Keaton Jennings for example. This summer, he was made to look village by high pace around his off stump. In the Test just gone he feasted on finger-spin. Meanwhile, Lahiru Kumara, purveyor of 145 kph thunderbolts, was axed from the squad for being late to bed, with a false equivalence between his actions and what took place in Danushka Gunalathika's hotel room. Sri Lanka need Kumara to take the new ball against such a fragile top three; he could also be greatly useful against the tail.
Meanwhile, the obsession with picking a mystery spinner meant that Akila Dananjaya was taken apart by a batting order that refused to let him settle. But mystery spin isn't the biggest weakness of this England side against spin: their biggest weakness is that they don't trust their defence. Therefore, you don't pick a spinner that will make them guess - you pick one that will make them defend. Notice how Dilruwan Perera was the pick of the bowlers in the last test?
My Sri Lankan XI to face England would likely be:
1. Dimuth Karunaratne
2. Kaushal Silva
3. Dhananjaya de Silva
4. Kusal Mendis
5. Angelo Mathews
6. Angelo Perera or Roshen Silva (in place of injured Chandimal)
7. Niroshan Dickwella (wkt)
8. Dilruwan Perera
9. Suranga Lakmal
10. Chanaka Komasaru (or similar spinner)
11. Lahiru Kumara