Man United turn to Giggs for comeback bid
Manchester United's Dutch striker Robin van Persie (R), Belgian midfielder Marouane Fellaini (C) and Welsh midfielder Ryan Giggs (L) take part in a training session in Manchester on February 24, 2014 - by Paul Ellis
United are seeking to overcome a 2-0 deficit from the first leg and Moyes picked an attacking line-up, with Antonio Valencia and Danny Welbeck on the flanks and Wayne Rooney partnering Robin van Persie up front.
In all, Moyes made four changes to the team beaten 3-0 by Liverpool at Old Trafford on Sunday, with Giggs, Valencia, Welbeck and Rio Ferdinand the players coming into the side.
Marouane Fellaini, Adnan Januzaj, Juan Mata, who is cup-tied, and captain Nemanja Vidic were the players to drop out.
Giggs, 40, is one of the most experienced players in Champions League history, but he has made only two starts for United since the turn of the year.
Newly recrowned Greek champions Olympiakos made only one change to the team that started the first leg, with David Fuster coming in for unwell Nigerian forward Michael Olaitan.
Argentine striker Javier Saviola was not named in the match-day squad due to a thigh problem, having played only a limited part in Tuesday's eve-of-game training session.
Starting line-ups for the Champions League last 16 second-leg match between Manchester United and Olympiakos at Old Trafford on Wednesday (1945 GMT kick-off; Olympiakos lead 2-0 on aggregate):
Manchester United (4-2-3-1)
David de Gea; Rafael da Silva, Rio Ferdinand, Phil Jones, Patrice Evra (capt); Michael Carrick, Ryan Giggs; Antonio Valencia, Wayne Rooney, Danny Welbeck; Robin van Persie
Coach: David Moyes (SCO)
Roberto; Leandro Salino, Kostas Manolas, Ivan Marcano, Jose Holebas; Giannis Maniatis (capt), Delvin N'Dinga; Joel Campbell, Alejandro Dominguez, Hernan Perez; David Fuster
Coach: Michel (ESP)
Referee: Bjorn Kuipers (NED)