Yousuf, 35, has come out of international retirement to help bolster the batting line-up of a Pakistan side thrashed by 354 runs in the first Test at Trent Bridge last week.
And spinner Swann admits Yousuf, who averages more than 53 in his 88 Test matches to date, says England would be foolish not to take notice.
“We don’t focus too much on what the opposition are doing but obviously when a player of Yousuf’s ability comes into their team you have to sit back and say ‘how are we going to attack this player?’ ‘how are we going to nullify that threat?’, said the Nottinghamshire bowler.
“Obviously he is a threat, he’s a world class player, but I think the way we are bowling at the minute, especially Jimmy [James Anderson] and Frank Finny [Steven Finn] up at Trent Bridge, we won’t really mind who we are bowling at.”
Anderson, in particular, was in full swing at Trent Bridge, using the overcast conditions to full effect, taking career-best match figures of 11-71.
And Swann was quick to heap praise on his great mate, but insisted England are keeping their feet firmly on the ground. “I think whoever we played at Trent Bridge would have had to play very well to counteract the swing bowling from James Anderson. I thought he was exceptional,” he added.
“They were quite unfortunate to find us in such good form with the ball at the start of a series, but we’re taking nothing for granted.”