The 21-year-old, who joined the fray by the 70th minute, set up Kenny Miller’s second goal and scored another himself as the Gers picked a 3-0 away triumph at the Pittodrie Stadium.
The score read 0-0 as at Dodoo’s introduction.
“We didn’t get into the game well enough in the first-half and we were possibly worse in the second one,” Caixinha said, as reported by his club’s official website.
“The first 15-20 minutes of the second-half they were stronger than us and they pushed us to defend.
“That is the moment I identified totally the sacrifice of the team and their spirit in order to sustain what is going on.
“We knew they couldn’t take it that much, we knew they were taking risks and they were taking risks especially exposing the full-backs.
“That is the reason we tried to change something with Joe Dodoo on one side and Josh [Windass] on the other because they are quick players, they are very intense and they can fill space which is what the end result was.”
Sunday’s goal was Dodoo’s third in 15 league matches for Rangers. He has made the starting XI on two occasions.
The Kumasi-born joined the Scottish outfit on a four-year deal from English champions Leicester City in July last year.
He made one appearance as the Foxes won the topflight last season.