In normal circumstance, Zak Crawley would probably be looking forward to his trip to Australia on the England Lions tour.

And, in all truth, that's probably where he should be right now. He's 21, after all, and he has a first-class average that barely tops 30 with just three first-class centuries. Promising, for sure, but not quite ready for what may be the toughest job in the game: opening the batting in Test cricket.

But these are not normal circumstances. The injury to Rory Burns has robbed England of their most experienced opening batsman - yes, Burns has only played 15 Tests but a combination of his relative success and his maturity have seen him rise quickly in seniority - and Crawley has been the beneficiary. Having been drafted into the team to play in Cape Town at last notice - Burns injured his ankle the day before the game - Crawley would appear to have an excellent chance of retaining a place at the top of the order for the final two Tests.

England do retain other options. It remains possible that Joe Denly could be promoted to open the batting and Jonny Bairstow could be drafted in to replace Crawley. Equally, it is possible England could call up a replacement - probably Keaton Jennings, though James Vince could be another option - to move straight into the side.

But with Bairstow having had little chance to do anything to demand such a recall and the England management seemingly committed to providing extended opportunities for the younger players, it seems Crawley's position is pretty secure for the rest of the tour. Besides, it would be asking a great deal of any replacement to come straight into the side without acclimatisation.

"I'm taking one game at a time," Crawley said. "I'm putting all my focus on the Port Elizabeth Test now. Hopefully I can get a score there like Dom Sibley did in Cape Town and follow his footsteps and shore up my place in the side. But I'm not looking too far ahead.

"I knew the night before the game that Rory would be out for a number of weeks. So there were the usual nerves. But actually I was a lot better than my debut in Hamilton, so hopefully it'll be easier next time."

At this stage, the runs have not come. After two Tests - albeit, he only batted once on debut - he has an average of 10 and a top score of 25. And while he received a fine delivery in the first innings at Cape Town, he concedes that, in the second, he played "an average shot to a pretty average ball. It was a half-volley."

And yet there has been something about the way he has carried himself - his confidence in the field, his obvious fitness, his increasing calm in the second innings at Cape Town - that provides confidence. He may be "learning on the job", as his captain Joe Root put it, but he hasn't looked out of his depth. And it's clear the first taste he's had of Test cricket has left him wanting more.

Whatever happens, he has one great memory from his Test career. In taking the catch that all but clinched the second Test - a juggling effort in the slips that gave Ben Stokes his second wicket in as many balls - he played a part in a wonderfully dramatic final day. Even the manner in which he took that catch - accepting the need to parry the ball up and then plucking it one-handed at the second opportunity - suggested a certain cool in the heat of the moment.

"Stokes was bowling so fast," he said. "And we were so close to the wicket. It was just a matter of sticking my hand out and luckily I managed to make it go up in the air and get my other hand to it. It was a great moment when I saw it come down. It seemed to hover in the air. It lasted a lifetime.

"It was unbelievable when that last wicket fell. The whole experience was the best feeling I've had on a cricket field. The crowd singing for all five days was something I'll never forget. It was brilliant.

"You just want more and more of it. I can see why so many people work hard at this level. Once you get that buzz you want it every day of the week. I can't wait for the next Test. Hopefully it's the same again."

He does not think that Kagiso Rabada remembers him from their time at Kent. That's not surprising: by 2016, Rabada was already something of a star and Crawley was an 18-year-old member of the second team. He performed 12th man duties for the first team, but the pair did not play together.

Still, it tells you something about Crawley's innate self-confidence that he said, with just the hint of a smile, that he is looking forward to "taking him down" in Port Elizabeth.

"I thought I played him OK," he said. "And I loved it. It's always great shaping up against one of the best bowlers in the world and seeing how you go. I'm looking forward to playing him again at Port Elizabeth hopefully and taking him down."

If he manages that, he can start to think a lot more than one Test ahead.