Goals from Courtney Herbert and Steve Guinan secured victory for the Cobblers, but there was concern over the fitness of Konstantinou, who was stretchered off early on following a tackle from Richard Lavery.
Sampson was unhappy with the challenge that led to Konstantinou's withdrawal and told Cobblers Player: "There's no place for it. You can't make any excuse for that sort of tackle.
"But I'm sure Alex will be ok. He's walking away which is lucky for the lad. We'll assess it on Monday but he'll certainly be nice and sore on his shin."
Sampson confirmed the club are still in the market for a centre forward ahead of the new campaign.
"We are still searching," he added.
"We missed out on the boy from Leeds (Tom Elliot, who recently joined Rotherham on loan) so we move on to work on other targets."