The London club – currently perched third in the Premier League table after six games – play Unai Emery's side on Wednesday night and the Spanish striker played at their Mestalla ground three times during his time at former club Atletico Madrid.
Valencia drew their first group stage game 0-0 away to Genk but Torres, 27, warned that they are a different prospect when playing at home.
“It's a very difficult place to play away,” Torres told the Blues’ official website.
“Every time I went with Atletico, I can't remember once winning there.
“Valencia is one of the big teams [in Spain], but hopefully it can be different this time.
“It is a massive stadium with a very good atmosphere, I played with Atletico as an away team, but also as a home team with Spain, because we used to play there for important games three or four years back.
“The support there is fantastic, and it is like a lucky place for Spain. Every time we played there in an important game we won.
“I remember we played there against Lithuania when we were trying to qualify for the World Cup in Germany and we needed to win or we were out, and we won with a late goal.
“Before the game the stadium was completely full, even two hours before when we arrived on the bus the fans were waiting for us, so they gave us excellent support but it will be very hostile playing there as the away team which is good for Valencia.”
Chelsea won their first game of the tournament 2-0 against German side Bayer Leverkusen and if they succeed in winning away against Valencia they will have made the best start of any English side in this year’s Champions League.
Valencia lost for the first time this season away to Sevilla at the weekend but the former Liverpool striker believes their earlier 2-2 draw with Barcelona is evidence they have quality.
Torres said: “They played a really good game against Barcelona, especially for the first 60 minutes, and we have to be ready and waiting for them, expecting a tough game and a tough team trying to get the three points at home to get into the next round.”