The duo failed to find the net as Ally McCoist's side ended their four-game spell in North America with wins over Sacramento Republic, Victoria Highlanders and Ottawa Fury and a shock defeat to Ventura County Fusion.
Next up for the Light Blues is a clash with English Championship side Derby County this weekend and skipper McCulloch insists the goals will come from the prolific forward pair.
He said: "It isn't even a concern with Kenny and big Boydy. There is no concern about goals.
"I can guarantee that when the season starts it will be raining goals by those two.
"It is just getting the rest of the team sorted and settled and getting the new players in and getting them involved and getting a bit of momentum going."
McCulloch was pleased to end on a high note as their opening game of the campaign - a Petrofac Training Cup clash with Hibernian at Ibrox - looms nearer next week.
"It was a great way to finish the tour and to go back home with a positive result and positive performance," he told RangersTV.
"A couple of our performances at times in the games have not been what they should be.
"But I thought [on Thursday], right from kick-off we totally dominated."