The Ecuadorian winger made a big contribution to the Reds finishing above Bayer Leverkusen, Real Sociedad and Shakhtar Donetsk, a position which means the next, two-legged tie against Olympiacos will start in Greece on 25 February and then be completed in front of more than 70,000 United fans in Manchester on 19 March 2014.
Speaking to ManUtd.com after Monday's Champions League draw, Valencia said: "If we can do our job and get a good result over there, then we always feel confident at Old Trafford.
"We’ll take a lot of confidence from our performances in the Champions League so far this season. We qualified as group winners with a good points tally so confidence has been very high in the competition."
Valencia's own performances yielded two goals for his United account, home and away to Leverkusen. But even though both games ended in comprehensive victories for the Reds against one of the best sides in Germany, he won't be overconfident when Olympiacos are on the pitch in front of him.
"When it gets to the knockout stages of the competition you know there are no easy teams to play," Antonio added. "It’ll be tough but we’re focused on trying to get through [to the quarter-finals]."