Betis lost 1-0 to the Reds in Pittsburgh last night.
Pellegrini said, "In general terms, the evaluation is positive. We spoke with the players before the game about trying to maintain a physical rhythm, within the period in which we are prepared, and I think it was maintained.
"On scoring occasions it was more or less equal, we put good pressure in the opposite field, new players have adapted to what we are doing. The game was very useful, positive, and we are on the right path."
He added: "That's why I just said that it was very useful, new players were integrated, in the case of Adrián and Diego they already have to perform with the experience they have, but we also integrated Mendy, Lucas, Mateo, to Pablo García... Six or seven players who are starting their careers and who I think have also contributed a lot to this preseason."