The area which Guardiola was most careful about these days was not the training ground, but the team doctors. Iniesta and Milito had been injured in the game against RCD Espanyol. The team doctor had said at the time that Iniesta, who was only slightly injured, was likely to play against Nottingham Forest. So after playing in the "war of the century" with Real Madrid, he began to care about this issue, for fear of a relapse.
Iniesta was now the team's midfield core. He and Xavi managed things well in the midfield for Barcelona's offense. Barcelona was considered to be the team that played most beautifully on the planet at the moment, and it was to the credit of both of them.
Guardiola did not want to lose Iniesta when it came time to deal with the aggressive Nottingham Forest.
Aside from Gabriel Milito's slightly more serious injury, he wanted to come up with the strongest lineup to deal with a tiger like Tony Twain.