Bangladesh need a big win over the 2009 champions in their final group D match to advance to the Super Eights round but Ajmal's danger looms large after the off-spinner took 4-30 in Pakistan's 13-run win over New Zealand on Sunday.
New Zealand, who have already qualified for Super Eights, beat Bangladesh by 59 runs in the opening group match. The top two teams from the group qualify for the Super Eights.
Saqlain regarded as the inventor of "doosra" -- off-spinner's stock delivery which turns the other way and is mastered by Ajmal -- is currently serving as Bangladesh's bowling coach.
"Ajmal is a world class bowler but we have taken help from Saqlain who is very experienced but we have to execute our plans on the field and it's a do-or-die match for us but Pakistan is not unbeatable if we play well," said Rahim.
Ajmal is the leading wicket taker in Twenty20 internationals with 64 and his wicket taking ability poses a real challenge for Bangladesh, who have lost all their five matches in this shortest format against Pakistan.
"Playing Pakistan is a big challenge because their bowling is good but we want to put up our best to qualify for the next round," said Rahim, whose team only reached the second round in the inaugural World Twenty20 held in South Africa in 2007.
Since then Bangladesh have lost nine consecutive matches in World Twenty20 editions.
Pakistan captain Mohammad Hafeez said he feels blessed with a varied bowling attack, led by Ajmal.
"What else can you want when you have such a variety in your bowling attack," said Hafeez, who along with Ajmal and Shahid Afridi holds spin responsibilities, with rookie left-armer Raza Hasan in reserves.
"As a captain it is a blessing for me. This is something I am very pleased to have that I have so many options in bowling and whenever I throw the ball to any of my bowlers he is ready to bowl," said Hafeez.
Hafeez, however, said Bangladesh will not be taken lightly.
"We are not thinking that we have already qualified, we have to win against Bangladesh. They have lost their first match so they will come down hard on us. We are not going to take Bangladesh lightly," said Hafeez.