The belief that "it is not the English style" and that "Vialli would not want the stain on his reputation" give them hope. But like the bookies they remember matches such as West Germany's with Austria, in the 1982 World Cup, and worry. Then Horst Hrubesch's early goal was followed by 80 minutes of inaction, enabling both sides to go through to the next round at the expense, on goal difference, of Algeria.
Tonight Chelsea and Hertha do not even have to bother with a goal: a scoreless draw would send both into the next lucrative stage of the Champions' League at the expense of Milan. The Italian champions, who must beat Galatasaray in Turkey to stand any chance of progressing, would then have to settle for a Uefa Cup place alongside Arsenal, assuming they do not lose in Istanbul.
That Milan could well pose a threat in the later stages of the Champions' League - should they survive - is an added incentive to Chelsea to see them depart but, for the reasons expressed above, the presence of 34,000 fans wanting good value for their expensive seats, and, above all, the intervention of the chairman Ken Bates, suggests they will approach the match intent on winning it.
Bates' input, made to Chelsea Clubcall, dominated yesterday's press conference. The chairman accused the team of "surrendering" during the 3-2 home defeat to Arsenal and said there had been "errors of selection" in recent weeks, during which Chelsea also lost to Watford, Liverpool and Derby.
Gianluca Vialli, like his team at Pride Park, offered no defence but defused the comments with masterful diplomacy. He said: "I respect his opinion and accept the criticism. I have made mistakes. With the team we have, if you are perfect it is quite difficult to lose games, so I must have done something wrong.
"Against Arsenal we were the better team, but it was a very bad performance against Derby. It is not on purpose but in the back of our minds we approach games at the San Siro differently to the games at Watford or Derby. Now we have to make up for it with a good performance.
"Players sometimes react to criticism with better performances, but if we lose the chairman will not be happy and neither will I. We want to win and I want us to do so in style. A fake match would annoy me. It is nothing to do with my being Italian; our supporters have paid for their tickets and expect us to do our best and a fake match is not good for football."
The scenario is similar to that when Manchester United drew at home to Bayern Munich in the group stages last year. Though the formula for qualifying was different then, when both sides realised, late in the game, that the 1-1 score would put both of them through, and attempts on goal dried up completely.
That may be the case tonight. Jurgen Rober, the Hertha coach, said: "I think we will be put under pressure as it is not the English way to play for a draw. But, maybe in the second half, if it is a draw with 15 minutes to go, everybody will be happy."
Indeed, as Vialli added: "Do not expect us to be silly and attack with 11 men just to show we are trying to win."
Not that winning will be easy. Chelsea were comprehensively out-thought and largely out-fought when losing 2-1 in Berlin in September. The right- back Albert Ferrer intimated yesterday that they had underestimated Berlin and they will probably pay closer attention to the Iranian international Ali Daei, who scored both goals, this time.
Like Chelsea, Berlin have only won once in five matches, but the astute Rober, a former Nottingham Forest player, is likely to have his team well organised with the accent, as in Berlin, on defence and counter-attack. Rober added: "I am surprised Milan have struggled but I hope they lose in Galatasaray. That way it does not matter what happens here."
Chelsea (probable): De Goey; Ferrer, Desailly, Leboeuf, Babayaro; Petrescu, Deschamps, Wise, Poyet; Zola, Flo.
Hertha Berlin (probable): Kiraly; Herzog, Rekdal, Van Burik; Sannah, Deisler, Sverrisson, Wosz, Michalke; Preetz, Daei.
Referee: K E Nilsson (Sweden).