Fabregas, 22, came through Barca's youth programme before joining the Gunners as a 16-year-old in September 2003 and is in the prime of his career, while Henry, a decade older and in the twilight of his, scored a record 226 goals in his eight years with Arsenal before joining the Catalan side in 2007.
The two-legged tie is given even more piquancy by the persistent rumours in Spain and England linking Fabregas with a move to the European champions, where five of his Spain team-mates, including defender Gerard Pique, ply their trade.
"He is the one who fires the Arsenal engine," Pique said at a news conference on Friday.
"For sure there are other good players who compliment him but Cesc is the most important."
Guardiola's Arsenal counterpart Arsene Wenger, who also coached Henry at Monaco, said on Friday he maintained close contact with his French compatriot.
"But I believe what is important is on the day that everyone sees a good football game and that we win it," Wenger told a news conference. "The best way is to focus on us and not too much on our opponents."
For that reason, Fabregas is likely to be a much more decisive figure in the tie than Henry, although the Frenchman's form has picked up in recent matches and Pique said he was getting back to his best.
"It's very important for us that he is firing on all cylinders," he said.
Barca assistant trainer Tito Vilanova, who coached the young Fabregas, said on Friday it was inevitable that attention would be focused on the Spain midfielder but noted that "Arsenal would not be here if they did not have other quality players".
"Whatever happens, it's a lack of respect to talk about his future because he is currently an Arsenal player," Vilanova told Barca TV.
Follow FFT.com on Twitter
Join FFT.com on
