Chelsea aim to claim a place in the Champions League final by avoiding defeat to the holders tonight.
Barcelona are set to welcome Gerard Pique back into the side as they hope to recover from back-to-back defeats, in the first leg at Stamford Bridge and then to arch rivals Real Madrid on Saturday.
Puyol and Mascherano are walking a suspension tightrope, a booking for either would rule them out of the final in Munich.
Pep Guardiola has a full strength side to chose up, with the exceptions of long-term absentees David Villa, Eric Abidal and Andreu Fontas.
At a press conference at the Nou Camp, the Barca manager looked frustrated and swore in one response but said: "I don't know if this is the most important moment of my career as a coach, but I have always faced these challenges with a lot of optimism as I believe in my players and team."
"Whenever you have a defeat, the day after the match you feel a little low but afterwards you get faith in the facts and I am optimistic because I know them well and that we will work hard."
Chelsea boss Roberto Di Matteo should revert back to the same team that beat Barcelona in the first leg, after resting some players for the game with Arsenal on Saturday.
Didier Drogba has been suffering with a slight knee problem and could miss out, David Luiz will definitely miss out.
Branislav Ivanovic, Ashley Cole and Ramires are all one booking away from missing a potential Champions League final place in Munich next month.
Defeat for Barcelona would see them lose their third game in a row for the first time since early 2003, when they suffered at the hands of Valencia, Celta Vigo and Atletico Madrid.
Barcelona Form: L, L, W, W, W
Possible starting XI: Valdes; Alves, Puyol, Pique, Adriano; Xavi, Busquets, Iniesta; Sanchez, Messi, Pedro
Chelsea Form: D, W, W, D, W
Possible starting XI: Cech; Ivanovic, Cahill, Terry, Cole; Mikel, Meireles; Ramires, Lampard, Mata; Drogba
Barcelona v Chelsea - view commentary, squad, and statictics of the game live.
Source: DSG
Source: DSG