Danny Cowley welcomed the stern test provided by Coventry ahead of the new League One campaign.
The Championship side ran out 2-0 winners at Fratton Park, with Viktor Gyökeres and Joe Panzo on target after the break.
And Josh Griffiths prevented further damage by keeping out a late penalty from former Pompey loanee Tyler Walker.
The hosts had chances of their own, though, with Simon Moore making fine saves to deny Louis Thompson, Colby Bishop and Ronan Curtis.
Cowley conceded that there is still some fine tuning ahead of next Saturday’s trip to Hillsborough, but believes his side are on the right track.
The Blues boss said: “It was a great test for us against a well coached Coventry side who have been together for a long time.
“They ask an awful lot of questions of you against a ball and in the first half, I thought we did ever so well.
“I was really pleased with how we performed and we stopped them from playing through us, which they love to do.
"We suffered in the final few minutes against a top side, but there was a lot of learning from us and we’ve got work still to do."
“I did think we could have been a bit braver with the ball and goals change games – Coventry were able to get a good place in the game after the break.
“We gave away possession from our own free-kick and they countered to score, but we had some great chances after that to get back into it.
“That was a positive sign and if we’d have put one of those opportunities away, then it becomes a different game.
“But instead we gave a soft goal away from a free-kick and that possibly doesn’t happen if you’ve got Sean Raggett in there.
“We suffered in the final few minutes against a top side, but there was a lot of learning from us and we’ve got work still to do.”
New signing Bishop came on at the start of the second half to make his first appearance in a Pompey shirt
Cowley said: “Colby came in and trained on his own on Thursday and then joined the group for the first time on Friday.
“There was an opportunity for us to connect him up with the team and it was great to have him with us.”