The surface for the second Ashes Test should be slower than in Brisbane, but neither side is likely to make radical changes

The drop-in pitches at the Adelaide Oval have been under wraps for two days to protect them from temperatures that rose to 38C in the shade and the drizzle that accompanied a sharp change in wind direction which dropped the temperature to the mid-20s.

The idea that the covers have been hiding either hot-house cultivated replicas of the old Adelaide pitches or Gabba-clones to order for Mitchell Johnson are wide of the mark, despite assertions that Johnson will be able to carry on where he left off in Brisbane: spin is not only the prerogative of Graeme Swann and Nathan Lyon.

These are early days for the Adelaide drop-ins, the first season in which they have been used. The two Sheffield Shield matches played on them, both drawn, have been revealing. In the first, batsmen predominated and bowlers suffered as South Australia made over 600 against Western Australia in a game that saw 1,237 runs and only 23 wickets.

The second match, in which Tasmania were South Australia's opponents, saw even more runs, 1,286 but 32 wickets, although the game was played at a turgid pace early on and ended tamely after South Australia had been set 385 to win in 46 overs. Three centuries and one double hundred have been scored.

Before the season the character of the pitches was an unknown quantity, so preparation has been as much about experimentation as it has about producing standardised surfaces. For the Western Australia match, the groundsman, Damian Hough, left 8mm of grass and found this too unforgiving for bowlers, with nothing for the seamers and no turn for spinners, of which South Australia fielded two.

For the second match, he halved the grass length to 4mm, and ended up with a sluggish surface although one not without some bounce, albeit of the slow tennis ball variety. The former Australia batsman Marcus North, who opened the batting for Western Australia and was therefore one of the first to bat on a new pitch, made 110 and 84 not out, so had plenty of time to assess it. He has described it as being like the early Melbourne drop-ins, which were not low but were definitely slow.

Given these results there has been speculation that both sides could make some radical changes, with talk of England thinking about including two spinners, bearing in mind that this is the balance that South Australia have gone with; and Australia omitting their twin spearheads of Johnson and Ryan Harris in order not to flog them on an unforgiving pitch and thus save them for what could prove the pivotal third Test in Perth.

Neither is likely to happen. In Brisbane, Johnson and Harris were scarcely extended physically, sending down 38 and 34 overs respectively in the 381-run win, and Australia would want to press home the advantage that the two have gained, no matter what the surface. There would also be the unthinkable possibility that they were omitted and England won the match to square the series, which if nothing else would lead to the selectors being pilloried. Even on sluggish pitches, bowlers who deliver at upper 80s and into the 90s mph can cause damage.

In the case of England, they should be careful of inferring too much from the South Australia spin policy. One of them, Johan Botha, is captain and an all-rounder, while the other is Adam Zampa, a 21-year-old leg-spinner of whom South Australia coaches have high hopes for future international honours, and are therefore keen for him to gain experience. In other words, it is neither a policy to take advantage of turning pitches, nor one to ensure lots of overs as respite for seamers, on flat-tops.

It is also fair to point out that these pitches have seen matches of four days duration, and that a Test pitch, not least the old Adelaide Oval, can, on the fifth day, even late on, produce characteristics, be it variation in bounce or turn for spinners, that can alter the complexion of a game. There has been little clue as to how these pitches would have reacted had a game gone to five days, with better bowlers. Apparently, that for the Tasmania game did start to spin a little in its later stages.

For the Test, though, Hough is likely to head one of two ways. On the one hand, he could take the cut down even lower in the hope that the pitch might break up, although drop-ins do tend to hold together rather than crumble completely. On the other – and this is the most likely scenario – he could leave on extra grass and perhaps some moisture in it for the start of the Test in the knowledge that it will offer the seamers early help much as the old pitch did for England three years ago, but then flatten out, something that might take spin out of the equation.

In which case, whoever wins the toss could have a tough decision. The last time England played an Ashes Test on a drop-in, at the MCG three years ago, it was at the absolute insistence of the England bowling coach David Saker, whose knowledge of pitches there was second to none, that they should bowl first given the opportunity. They did so and, on Boxing Day in front of a huge crowd, famously bowled out Australia for 98 before lunch. Such expertise could prove crucial once more.