The Hearts winger was an unused substitute in both of those matches but his vantage point in the stands was good enough to know he does not wish to be anywhere near such heavy losses again.
The 20-year-old will have that in mind when he is restored to action at Tynecastle today, when his club side take on Celtic. There are better ways to prepare for the visit of the champions than to form part of a Scotland squad which lost 10 goals in two games without reply, but Walker has sough to make the most of the experience.
"The difference in those games was taking chances," he said. "We had a few last week and didn't take them and it cost us because Holland punished us. We need to make sure that doesn't happen against Celtic. If we get any chances we need to take them because you know Celtic will take theirs."
Hearts have looked in decent shape at home - on the pitch at least - following victories over Hibernian and Aberdeen to move within just nine points of second-bottom St Mirren. That has come amid the tumult of administration and a 15-point deficit to start the campaign, yet Hearts' young side has found something more nourishing to focus on.
"We're unbeaten at Tynecastle and we really want to keep our good run going there," added Walker. "We get a massive lift from playing there. There's nothing better than a full Tynecastle behind you. It spurs you on.
"I've not done well against Celtic in the past but hopefully that will change this weekend. Our home form is going to be massive this year. That's going to be key in us getting points."