The Blues came away from the Nou Camp with a hard-fought 0-0 draw last week and, although they failed to secure an away goal, Francis insists Chelsea still have a great opportunity of making the final of the Champions League for the second consecutive season.
"Chelsea would have loved to have scored," conceded Francis. "When you go away from home it's always important to score but I think Chelsea will shade it on Wednesday.
"They were on the back foot for most of the game in Spain and their best chance - Didier Drogba's double miss in the first half - was very much against the run of play.
"However, Guus Hiddink has proved himself to be tactically astute. He has received some criticism for Chelsea's defensive display in Spain but that won't bother him one iota. He sent his Chelsea players out to do a job and they did exactly that."
Francis also expects a similarly tight game in London, with Chelsea again attempting to contain their attack-minded opponents. "I don't think their tactics will be too different on Wednesday night.
Barcelona threat"I think he'll play as he did in the first leg and not open it up too much. The onus is on the home side to come out and score but if you leave yourself open and play an expansive game against Barcelona you will pay for it dearly because they are a very, very good side."
Francis also expects the Blues to stick with just the one striker up front, despite Drogba's impressive combination with Nicolas Anelka on Saturday against Fulham.
"I see no reason why Anelka and Drogba can't play together. The problem with playing two up front is you are left with a midfield four and Chelsea don't have a natural right sided player without Joe Cole.
"It's a waste if Michael Essien has to play there and although Frank Lampard started off on the right against Fulham that's not his best position either. I think they'll start with five in midfield and Drogba up front.
"Hiddink will also bring Ashley Cole back, no doubt about that. He was only absent because he was suspended and he'll return despite Jose Boswinga's performance in Barcelona. Ashley has had a good season, is back to his best form and I think he's an import player for Chelsea and gives them good balance.
"Everyone talks about Lionel Messi being a big threat for Barcelona - he is an outstanding player - but reverse their rolls and Ashley Cole is one of the best full-backs going forward in the world. That is one of the areas in which Chelsea can cause Barcelona problems."
United to scoreThe other semi-final sees reigning champions Manchester United travel to Arsenal with a 1-0 lead from the first leg at Old Trafford.
Francis believes the clash at the Emirates will be another tight affair but anticipates a replay of last season's Champions League final, with United avoiding defeat to progress to the final in Rome.
"My gut feeling is that it will be a score draw tonight which is the result which will suit Manchester United," said Francis.
"United have got so many good attacking options and I expect them to score.
Francis also expects Rio Ferdinand to return to the fold, after the defender's bruised lung kept him out of United's weekend Premier League win over Middlesbrough.
"Ferdinand and Nemanja Vidic are probably the best defensive partnership in Europe," stated Francis. "They've been outstanding.
"I'm sure if Rio is 100 per cent Ferguson would like to get him back in the team because he has got such vast experience."
Key men must shineArsene Wenger will be looking to his key men to perform for him at the Emirates, though Arsenal will have to improve substantially on their performance in the first leg, says Francis.
"Arsenal aren't dependent on one person but they'll be looking for a big performance from Emmanuel Adebayor and Robin van Persie.
"Adebayor was quiet in the first leg but he is a key man for them. It appears van Persie is back to full fitness and he'll also strengthen them offensively.
"I thought it was a very subdued and unusual performance from Arsenal at Manchester United last week. Arsenal must improve considerably from that performance, which I'm sure they will do.
"United, secretly, will be disappointed not to have more of an advantage after playing as well as they did in the first leg. That first half performance was as good as I've seen from Manchester United in a long, long time. Those missed chances could come back to haunt them.
"At the Emirates Arsenal have been very good over a long period of time but I think United will score.
"All four semi-final teams could make a case for going through to the final in Rome."