A segment for Channel Seven by Ricky Ponting during the lunch interval on the second day brought attention to the crater Warner had created in the batting crease as part of a plan to aid his footwork.

Unlike a normal batting guard where the marks run perpendicular to whichever stump the batter asks for, Warner dug what resembled a small trench parallel to the stumps with holes at either end.

Smith, who came in following Warner's dismissal shortly before lunch on the opening day, admitted it had taken him by surprise.

"I nearly fell in it," he joked. "I got used to it eventually but almost twisted my ankle a few balls to be honest then I sort of got used to it. I've never experienced that before on that side really, you occasionally get the edging of the footmarks at the backend of the game where you kind of fall into them where you are off balance, but when I'm moving to off stump and I've got this hole there it's something I haven't experienced before.

"I'd no idea it was coming until I walked out and marked my guard and saw this big hole. Was just wondering who made this? Think I asked Marnus [Labuschagne] what was going on at the end, there's a big hole I'm about to fall into. It was odd."

"Maybe he should it more often, it worked for me," he said. "He can keep digging that hole I suppose… whatever the batter needs I suppose to get themselves into a good position."

Warner, whose position has been under scrutiny, had made a compact 43 on the opening day, becoming increasingly assured after a tricky first hour, and later said it was as good as he had felt for 24 months.

Ponting, who is Warner's coach at Delhi Capitals in the IPL, explained that the method he was using was to aid his footwork and stop him going too far to leg stump.

"He's actually got a line going across the back vertical to the stump line," Ponting said. "And look at each end of that line there, there's two quite deep holes. Now I know for a fact, having worked with David Warner for the last couple of years, a lot on his batting, when he's batting his worst, his trigger movement has gone back outside leg stump.

"So only two days ago he came up with this plan of digging two holes and making sure that when he moved his foot that his foot stayed within those two holes. If he moved back and across, he could feel his heel going into the hole. If you move too far across to the off stump, then his toes go into the hole.

"That's the sign of a modern player, someone that's played over 100 Tests still trying to find a way to get better."

Although what Warner did was unusual, it did not contravene any Laws which only come into play for the protected area in front of the popping crease where bowlers are not allowed to encroach in to and batters are not allowed to enter "without reasonable cause" or take their guard in.