A Pools squad low on numbers were beaten 2-0 by the Scottish Premiership side in Portugal thanks to goals from Ewan Henderson and Ryan Porteous.
Hartley named just 16 players in his squad, with one of those being a trialist who came off the bench to replace the injured Tom Crawford, at the Amendoeira Golf Resort.
Crawford started the game as a centre forward for Pools with strikers Omar Bogle and Marcus Carver being unlisted during the fixture in the Algarve.
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Bogle has been subject to speculation linking him with a move to Newport County as Pools boss Hartley re-emphasised the need to bring in attacking reinforcements.
“It was as I expected for the game in terms of how it would go,” said Hartley.
“We had to work really hard. They’re well in front of us. They’ve got some really good players - you saw the changes they made.
“They had two XI’s whereas for us, we were struggling to even put a team together.
“It wasn’t ideal preparation. But in terms of the work rate from the players it was terrific.
“We know what we need to do and who we need to bring in and the type of player we need to bring in.
“We’re short at the top end of the pitch so we had to play a midfielder as a sort of makeshift striker, but the pleasing thing is the 90 minutes some of them got under their belt. That will benefit them over the course of the next few weeks.”