Attacking midfielder Abdi, recruited for an undisclosed fee, thought to be in the region of £4m from Watford last month, was taken off and replaced by Fernando Forestieri.
Carvalhal said it was a tactical change, claiming Abdi was a “little tired”.
“When Abdi arrived, he hadn’t played many friendly games,” he told The Star. “We received him more late than others.
“He played very well against Aston Villa and Norwich City. He run and fought a lot but I thought he was a little tired and wasn’t his normal self against Burton.”
The Portuguese boss has spoken of his relief over the Forestieri saga having finally been resolved. The striker, who refused to play in Wednesday’s goalless draw against Norwich last weekend amid speculation linking him with a move away from Hillsborough, has said sorry to his teammates, Carvalhal and the club’s fans over the last 48 hours for his “unprofessional and unacceptable” behaviour.
On Forestieri’s second half contribution, Carvalhal said: “It is not easy when you come on to play in a high tempo game but Fernando played how he usually does.
“He created situations and problems to the opponent and we had one or two situations where we could have scored.”
Jose Semedo is currently receiving treatment from Wednesday’s medical team after hobbling off in the first half of their 3-1 loss at the Pirelli Stadium.
Carvalhal, who wants to sign a new left-back, centre-half and left winger before the August 31 transfer deadline, is confident Tom Lees will be back in the first-team fold for Saturday’s Yorkshire derby with Leeds United. Lees missed the trip to Burton because of a foot problem.