Liverpool's Carragher and Arbeloa in on-field scuffle
The Spanish tactician explained the disagreement as a sign of a winning mentality.
The pair squared up after The Baggies had a chance to reduce the two-goal deficit.
Referee Martin Atkinson gave both players a stern talking to after Xabi Alonso had managed to separate them.
"You could see Carragher and Arbeloa because we wanted a clean sheet and they were a little bit nervous," reasoned Benitez.
"Arbeloa was going forward and then we had some problems in defence. We wanted to protect Pepe Reina because now I think he has 20 clean sheets - Van der Sar has 21.
"It's a positive message in terms of the mentality of the team. We wanted to show character and a winning mentality."