Pompey'S slide into possible relegation trouble continued as Thierry Henry returned from injury with a hat-trick.
The Blues have only claimed four points out of a possible 30 since late December - failing to beat Norwich and Blackburn at home in the process and only beating Middlesbrough.
Assistant boss Joe Jordan said: "We've got matches left that we can win and we've got to show that we're a Premier League club.
"We're still looking at reaching 40 points, which would be 10 points from nine games, but we could need less."
Arsene Wenger, meanwhile, backed Henry to deliver against Bayern Munich in the Champions League this week.
Henry accepts the pressure is on him to deliver a riposte to his critics who say he goes missing in really big games for the Gunners.
"I still see people talking about me, whether I'm scoring enough," he declared.
"But look at the stats - not only have I scored 22 league goals this season but I'm on 14 assists, which isn't bad for a striker.
"I try to do my talking on the pitch. I know, once again, that if I don't score on Wednesday, it will be blamed on me, so I'm preparing myself for that!"
Wenger is even more insistent, having seen Henry pull Pompey apart with the sixth hat-trick of an Arsenal career that has seen him score 177 times for the club, eight behind Ian Wright's record.
"Thierry is always under big pressure as people get used to him scoring goals for fun, so when he doesn't deliver, they ask what's wrong," observed the Arsenal boss.
"But you must always consider that what he does is exceptional and you get spoilt by what he does deliver.
"The Champions League is more difficult but his record in that is very good. And who can deliver three goals in every Champions League game?"
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