Kenny Jackett wants Pompey to rediscover their clinical touch at Oxford on Saturday.
They were below their best in a rare defeat suffered against Blackpool last week, failing to register a shot in the first half.
With promotion rivals Sunderland and Luton playing out a draw, there is still a four-point buffer at the top of the table.
But Jackett expects an improvement against a side who are currently sitting just inside the League One drop zone.
The Blues boss said: “We didn’t do enough going forward against Blackpool, although didn’t do badly defensively.
“It ended up being a narrow defeat and so we’ll be looking to find some cutting edge and creativity at Oxford.
“We want to make sure that we’re more incisive in the final third to be the goal threat that we usually are.
“I would suggest that most sides would know a lot about each other as they face them for a second time.
"We want to make sure that we’re more incisive in the final third to be the goal threat that we usually are."
“There have been a couple of occasions when I’ve watched Oxford this season and there’s a lot of talent there.
“We know that they will be pushing as hard as they can to get away from that battle against relegation.”
Pompey have tied defender Jack Whatmough down to a new deal, although winger Andre Green has been recalled from his loan spell by Aston Villa.
Jackett said: “Jack’s contract is very well deserved. He’s had an excellent season so far and has been consistent, while physically he’s in the best shape he’s ever been.
“His contract was running out in the summer, so we’re delighted that he’s committed his future to Pompey.
“I got a call from (Villa manager) Dean Smith, who said they were recalling Andre because of their quota of English players.
“He scored some key goals for us, so we’d like to thank him for that. It was a surprise, but you always know it can happen during the window.”
Jackett is hopeful of having a couple of extra players available to face Oxford following spells on the sidelines.
He said: “Ben Close and Lee Brown should both be fit and available for this weekend – they’re the only likely additions.
“I don’t think Oli Hawkins will make the QPR or Luton games – it’s more likely that he’ll be ready for Doncaster. The only other ones out at Luke McGee and Nathan Thompson.”