Bryan Robson believes West Brom must win three of their remaining five matches to have a realistic chance of securing Premiership survival.
Robson has set his side the task of winning their remaining home games with Bolton and West Ham plus one of the away matches at Arsenal, Newcastle or Everton.
The Baggies have produced some stirring performances in recent weeks against the likes of Chelsea, Manchester United and Tottenham for little tangible reward.
But they have collected only two points out of the last 24 and, with Portsmouth having an easier looking run-in, Robson knows Albion must regain the winning touch sooner rather than later as they prepare for Saturday's encounter at Highbury.
Robson said: 'We need three wins to stay up, and even then it might not be good enough, but that's got to be our aim. We've got to win our last two home games and get an away win from somewhere.
'That's why it was annoying not to win at Villa last weekend given the way we played.
'I don't care what David O'Leary says about a draw being a fair result, we dominated that game in the second half.
'When you are playing as well as that in an away game, it's frustrating not to get the three points.
'Hopefully in the next three away games we will play as well as we have in the previous three at Birmingham, Tottenham and Villa. If we do that, I am sure we will win a game.'
Robson has been frustrated by injuries to strikers Geoff Horsfield, Kevin Campbell and Nathan Ellington when they have been hitting top form this season.
He added: 'Goalscorers are always so important in your team and this season has been frustrating because of the injuries to strikers.
'When I look back over the whole season, as soon as my strikers have started getting on a scoring run then 'bang', an injury comes along and they're out of the side.
'It has interfered with them going on a longer run and keeping on scoring and we have been unfortunate that way.
'Look at Nathan. He scored as a substitute against Birmingham, he scored against Man Utd and I'm thinking his confidence is sky high and he's starting to score goals again.
'I put him back in the team and he is injured in the second game back. That just about sums things up.'
Ellington is the only injury doubt for the clash with the Gunners because of a foot injury.
Robson said: 'Hopefully he is going to be okay. He is a little bit sore still but he came through training okay on Thursday and in another two days he could be 100 per cent.'