Los Pericos came from 2-0 down to beat lower league Mirandes in midweek but lost Alvaro Vasquez to a hamstring injury that will keep him out for a month, whilst Sergio Garcia has had an operation on his meniscus and Walter Pandiani has suffered a setback on his return to fitness.
Pochettino told AS: "The reality is two players got injured on the same day on top of the problem with Pandiani.
"Everything would indicate that we will sign a forward, although I shouldn't speak too much about it as the man in charge is (sporting director) Ramon Planes."
The Copa del Rey comeback against Mirandes was just one of many completed in recent weeks and Pochettino believes his side are starting to become mentally strong.
"We are trying to change things, we want to generate a positive atmosphere. There are some things that are deep-rooted in the structure and mentality of the club, but slowly but surely we are starting to turn those around. It isn't something that can be done in a day, but with time and above all the help of everyone at the club, we are doing something right to change the mentality."
With Thievy Bifouma now Pochettino's only striking option the 19-year-old seems set to retain his place in attack with scorers from Tuesday night Vladimir Weiss and Joan Verdu supporting from midfield.
Granada have selection problems of their own ahead of the trip to Barcelona with goalkeepers Roberto and Jose Juan out through injury so on-loan Benfica keeper Julio Cesar will make his debut.
There are also problems in defence as Inigo Lopez is suspended and Pape Diakhate is away at the African Nations Cup so new-signing Borja Gomez could go straight into the side.
Facing Espanyol will be a special occasion for one Granada player as Moises Hurtado plays for the first time against the side he spent almost two decades with.
He said: "It will be very special to play against the club that I have spent most of my life with and have great memories of.
"They are doing very well, they are very aggressive and have determined players in the forward areas, but if we don't commit errors and take our chances I feel we can make an impression on them."