Luis Enrique's team lost ground to La Liga leaders Real Madrid on Saturday as they were held to a 0-0 draw at Getafe.
Lionel Messi rattled the crossbar with a free-kick and the visitors missed a host of chances, although the combination of tenacious opponents, persistent rain and a tricky playing surface meant Barca struggled for their customary rhythm.
Sporting director Andoni Zubizarreta told reporters: "We didn't pass the ball quick enough, although we had chances and failed to make the most of them.
"We played our classic game with a 4-3-3, but Getafe didn't give us much room.
"The ball bobbled for long spells, and the water made [the pitch] become unstable. We didn't find much help out there."
Neymar missed the trip to Getafe due to a minor ankle injury and is unlikely to be risked against Huesca, while the Brazil star's compatriot Dani Alves is also sidelined with a hamstring problem.
Iniesta and Rafinha were named among the substitutes at Getafe so could start in midweek alongside goalkeeper Marc-Andre ter Stegen, who has played all Barcelona's cup games this term since signing from Borussia Monchengladbach.
Heading into this weekend's fixtures, a solitary point separated the top five, with Huesca second behind leaders Athletic Bilbao B on goal difference.
And Luis Tevenet's team moved to the top of the pile in emphatic fashion with a 6-1 win over Trival Valderas, rediscovering their scoring touch after goalless draws against Conquense and Fuenlabrada followed the Barcelona reverse.
