Pep pondering over defensive puzzle
Eric Abidal, who is enjoying one of his best seasons in the Catalan capital, has successfully switched over from left-back several times already this season, while Sergio Busquets has shown impressive versatility in dropping back from his normal defensive midfield role when required.
Gabriel Milito may be given a rare Champions League start, although the 30-year-old has looked short of pace since returning from a long-term knee injury.
The La Liga leaders seek to overturn a 2-1 deficit from last month's first leg in London as they bid to reach the quarter-finals.
"If we don't get through tomorrow it won't be because Pique and Puyol are not there," Guardiola told a news conference on Monday. "A great team cannot allow itself to depend on players who are absent."
LIVE COVERAGE Follow it with the FourFourTwo team as it happens
Both Pique and Puyol missed last year's quarter-final, second leg against Arsenal, when Lionel Messi scored all four goals in a 4-1 win that put Barca through 6-3 on aggregate.
Busquets said he was ready to fill in in the back four.
"Of course they (Pique and Puyol) are very notable absences but we managed to win last year without them," he said.
"It's the coach's decision but I am ready to play wherever I am needed," the 22-year-old added.
"We have other players in the squad who can step in but wherever I play I feel very comfortable."
If Guardiola opts for Abidal and Busquets in central defence, Javier Mascherano would likely come into the midfield behind playmaker Xavi and Maxwell would step in at left back.
Arguably, the full-backs will be more important on Tuesday, as it was the pace of Arsenal's attacks down the flanks that caused Barca the most problems in the first leg.
Guardiola expects Arsenal to try to deny his players the space to attack and attempt to cause damage on the break using speedy players like Samir Nasri and Andriy Arshavin.
"We'll have to attack with more discipline than ever because they are very dangerous on the counter," he said.
He dismissed a question that referred to Arsenal's apparent inability to deal with pressure.
"Right now they are competing at the top of the Premier League, they were in the final of the Carling Cup and they always get far in the Champions League," he said.
"When they are competing every season at the top it's because they are quality."