Only three teams in the entire EFL have taken maximum points at this stage of the season.
Pompey are one of them, with fellow League One side Peterborough and Championship outfit Leeds the others.
A resounding 4-1 victory over Oxford on Saturday ensured that Kenny Jackett’s side are in a confident mood.
But he has warned against complacency ahead of a couple of matches on the road in quick succession.
The Blues boss said: “Football is about looking forward – and we have to focus on facing Bristol Rovers and Doncaster pretty quickly.
“If we get too pleased or start patting ourselves on the back then we can get undone, so we brought the players in on Sunday morning.
"If we get too pleased or start patting ourselves on the back then we can get undone."
“We wanted them to look ahead to what is a big week and a hard one. They should take confidence from Saturday, but also learn what they can do better.
“This division is different to last season and I think it could be quite tight, with a number of sides ambitious to do well.
“There were times last term when we lost a lot of players, although you never like to use that as an excuse.
“But there’s no doubt we were short in certain areas and it’s something we’ve tried to address this time.”
Rovers recovered from successive league defeats to get their first points on the board with a win at Wycombe on Saturday.
Jackett said: “They have a good squad of players and an excellent manager, with an impressive home record over a number of years.
“We’ll have to be at our very best to get anything from the game and will need to work hard. We want to perform to our maximum.”
Dion Donohue and Nathan Thompson were the only players unavailable for Pompey at the weekend.
Jackett said: “They’re both back working with the group. I think Dion will miss the next couple of games, but he’ll be training hard this week.”