Champions League team news: Last season's beaten finalists Liverpool were without midfielder Xabi Alonso, who has failed to recover from an ankle problem initially sustained at Portsmouth on Saturday, and aggravated last night in training at the Estadio Do Drago.
Boss Rafael Benitez made six changes from the side that drew at Fratton Park, with Sami Hyypia at the back, Steven Gerrard, Javier Mascherano and Ryan Babel in midfield with what looks like his first-choice front pairing of Fernando Torres and Dirk Kuyt.
Although Porto have not lost in nine home Champions League games against English sides — including the big four of Liverpool, Chelsea, Arsenal and Manchester United — the Anfield men's record of just three defeats in their last 17 away European group games certainly boosted their confidence ahead of this opening Group A clash.
Celtic manager Gordon Strachan drafted in midfielder Paul Hartley at the expense of Aiden McGeady for their game against Shakhtar Donetsk in the Olympiyskiy Stadium.
The Scottish champions beat Inverness Caledonian Thistle 5-0 at home at the weekend to go top of the Clydesdale Bank Premier League but that was not enough for the Republic Of Ireland player, one of the Hoops' best performers on the day, to keep his place.
Jan Vennegoor of Hesselink joined Scott McDonald in attack as the Parkhead side sought their first away win in the tournament.
Shakhtar's Romanian coach Mircea Lucescu, who had planned the 3-0 defeat over Celtic at the same venue three seasons ago, paired Italian ace Cristiano Lucarelli with Brazilian star Brandao in his attack.