Sir Bobby looks set to hand Shola Ameobi the crucial forward role in the Nou Camp tonight, in the absence of Craig Bellamy and Alan Shearer.
He will also decide whether to pair Shola with Lomana Lua Lua or use a five man midfield with Gary Speed returning alongside Jermaine Jenas and Kieron Dyer.
Titus Bramble is available again and may replace Andy O’Brien or Aaron Hughes in the centre of defence.
Barcelona are definitely without the injured Luis Enrique and Gabri and the suspended Fernando Navarro, and coach Louis van Gaal looks set to make changes after their shock defeat at Rayo Vallecano on Saturday.
Michael Reiziger, Gaizka Mendieta and Marc Overmars all look set for recalls, which means Argentinian striker Javier Saviola should start on the bench.
United: Shay Given, Andy Griffin, Titus Bramble, Aaron Hughes, Olivier Bernard; Nolberto Solano, Jermaine Jenas, Gary Speed, Laurent Robert, Kieron Dyer, Shola Ameobi.
Barcelona: Roberto Bonano, Michael Reiziger, Carles Puyol, Frank de Boer, Thiago Motta, Gaizka Mendieta, Xavi, Philip Cocu, Juan Roman Riquelme, Marc Overmars, Patrick Kluivert.
Referee: Frank De Bleeckere (Belgium).