Iniesta was forced off during Barca's 1-0 La Liga defeat of title rivals Atletico Madrid on March 4 and has not played since, missing the weekend win over Malaga.
'We are talking about two different players, ' said Conte.
"Tomorrow is a must-win situation so you need to take risks, as long as they are not too excessive".
"For me, Messi is the best player in the world and in history".
With Iniesta absent and Lionel Messi unavailable due to the birth of his third son, Ousmane Dembele excelled in Barca's defeat of Malaga on Saturday and the France worldwide is a contender to start against Chelsea.
A 1-1 draw from the first leg makes Barca slight favorites to qualify, but Valverde reminded journalists present in his pre-game press conference that Barca had suffered for much of the first leg before Leo Messi scored the vital away goal.
Chelsea head coach Antonio Conte knows his side must score and "suffer" at the Nou Camp.
"There is no magic formula to going through except to be better than they are", he commented, warning that Chelsea are the "best team in the Premier League on the counter-attack", and that Brazilian striker Willian, who scored for Chelsea in Stamford Bridge and also hit the post twice in the game, "has been in great form recently and scoring goals easily".
'Hazard is more of a no.10, Iniesta is more of a midfielder who stays in the centre of Bacelona's play.
Chelsea played with Eden Hazard in an advanced role instead of an out-and-out striker in the first match at Stamford Bridge, but Conte said Alvaro Morata is in contention to play in the second leg.
"We played a really good game and nearly a flawless game".
However, Puyol, who won the competition three times, is mindful that Barca were also in charge of their two-legged contest six years ago only to be stunned by a 10-man Chelsea side who won 3-2 on aggregate. Chelsea have shown that they are a very organised team with clear ideas about how they want to play and players up front who are very risky and very quick. But when they push back and defend strong they are hard to break through.
"They can hurt you a lot on the counter-attack so Barcelona will have to put in a serious performance and try to score a goal because if they don't Chelsea could hurt them on the counter". We did all we could to score another goal but Fernando scored the second on the counter-attack and eliminated us.