Pakistan's Imam-ul-Haq said this weekend's "huge-pressure" World Cup game against arch-rivals India was a must-win clash for his side after their defeat by Australia.

Wednesday' 41-run loss to the reigning champions in Taunton left Pakistan eighth in the 10-team table and with plenty to do if they are to qualify for the top four, who will contest the semi-finals.

Asked if the reverse at Somerset's headquarters meant Sunday's match at Old Trafford was now one Pakistan simply had to win, Imam replied: "Yes, we've had one game rained off, which was very important for us -- every game now is very important for us, so yes you can say that."

"Obviously, to be part of that kind of game, it's great. It's in Manchester, lots of Pakistani fans there -- so I'm really excited about it. It's a huge pressure game, obviously.

"Pakistan and India, there's a lot of mysteries behind that but we want to just focus on our cricket strengths and how we can get better."

Set a target of 308 to beat Australia, Pakistan were going well while Imam was at the crease making 53.

But he fell in tame fashion, gloving a legside ball from Pat Cummins he could have left alone to wicketkeeper Alex Carey.

So disappointed was Imam, he could barely drag himself from the crease before trudging back towards the pavilion.

Pakistan continued to lose wickets steadily and, despite a late flurry of runs from the eighth-wicket pair of captain Sarfaraz Ahmed and Wahab Riaz, were bowled out for 266.

"Obviously, I'm playing well, and this team depends on me and Babar (Azam)," said Imam. 

"When Babar got out (for 30), it was then my responsibility and I was going well but it was not a good ball that got me out, the same as I did against the West Indies," added the left-hander, the nephew of Pakistan great and selection chief Inzamam-ul-Haq.

"I knew I'd spent a hell of a lot of time on a tricky wicket so I knew it wouldn't be easy for any new batsman to come in. So it was a huge disappointment.

"If I've scored 30 in a winning side, that would be great, I'd be very happy.

"As a pro, if you're winning matches for your country, that's the best thing and if you're not, even if you score a fifty, that's a huge disappointment."

Feature image courtesy: AFP Photo/ Saeed Khan