With next month's EuroBasket tournament fast approaching, Great Britain faced tough opposition in Lublin, with Sweden able to boast NBA talents Jonas Jerebko and Jeffrey Taylor.
And despite Eric Boateng leading Great Britain with 14 points, closely followed by Kyle Johnson who had 13, it wasn't enough as Sweden ran out 85-68 winners.
Great Britain meet Poland next, which is followed by a double header against former world champions Spain before their EuroBasket opener against Israel on September 4, and Prunty insists they need to tighten up their defence before the tournament gets underway.
"Defensively, we had lapses, particularly late in the first quarter and into the latter part of the second quarter," Prunty said.
"So we had a stretch at the beginning of the game in the first five minutes and again in the first five minutes of the second where we calmed ourselves down, but those runs hurt us.
"We had a good third quarter and we talked at half-time about getting the lead down to ten and accomplished that goal and we wanted to continue that in the fourth but it just didn't happen."