So bad were the morning's conditions at Spey Valley – torrential overnight rain resulted in a two-and-a-half-hour rain delay as parts of the course were flooded – that the 34-year-old from Birmingham half-jokingly hoped he might even have done enough when he finished his second round on 11 under par for the event.
However he was also keen to make it clear that his extensive experience – he first held a European Tour card 11 years ago – means he is ready for anything over the weekend, with play due to resume today.
"I'm hitting it close, driving it well and putting everything in the right places," Walker said last night. "I hear the weather is going to be very bad tomorrow so I hope it gets cut to two rounds!
"People have seen me at the top of the leaderboard before, so I just have to take a lot more confidence out on the course."
In spite of the forecast, the likelihood of having to go the distance increased as yesterday went on as conditions steadily improved. Even so, what had been a five-shot lead when Walker walked off the course was reduced by only one. Garry Houston of Wales and Walker's countrymen Jamie Abbott, Simon Wakefield and Chris Lloyd were all tied in second on seven under par, the latter after shooting a stunning nine-under-par 62.
Walker knows, though, that umpteen players are capable of making a run at him, the depth of quality on the Challenge Tour having been underlined by the fact that in spite of those testing conditions, competitors had to break par to beat the cut.
No fewer than 15 of the 25 Scots in the field failed to do so, but Chris Doak, who won the Douglas Lowe Memorial Trophy for best Scot when it was presented for the first time last season, put himself in contention for a successful defence, as well as getting within touch of the leaders, with a second-round 67 that took him to five under.
That effort was all the more impressive given the fractured nature of his preparation which was down to more than the weather as a flatulent pet prevented him from getting a proper sleep.
"I was here at about 6.30am but then the delay came so I went back and made a roll and sausage. I have a house here and we'd been up all night because of the dog. It nearly knocked my caddy out last night. I'll put it in his room tonight," laughed Doak.