The Spain international made his comeback against Manchester City on Sunday after five weeks out with a knee injury which required surgery.
However, with Liverpool leading 1-0 from last week's tie at Anfield there is no need to risk the forward from the start as David Ngog is fit having missed the weekend game with an ankle injury.
Reds alert: Torres is put through his paces before heading to Romania
Midfielder Yossi Benayoun is pushing for a place in the starting line-up having also made his comeback - from a broken rib - at City.
With Maxi Rodriguez ineligible having already played in Europe for Atletico Madrid, Benayoun could contest the left-sided role with Albert Riera.
Defender Sotirios Kyrgiakos, currently serving a domestic suspension which rules him out of Sunday's match at home to Blackburn, is available but may remain on the bench as he did for the first leg.
Provisional squad: Reina, Skrtel, Agger, Carragher, Kyrgiakos, Insua, Gerrard, Lucas, Aquilani, Benayoun, Riera, Ngog, Kuyt, Torres, Cavalieri, Pacheco, Spearing, Darby, Babel, Aurelio, Degen, Kelly.
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