Bertrand and Holt both played a part in the 2-2 draw with Liverpool at Anfield on Saturday, the former being handed a start and the latter making an appearance off the bench.
El Ahmadi admitted that he was impressed by how quickly the Chelsea man, Bertrand, settled in particular after only spending one morning training with the rest of the team.
The Morocco international also believes that it is important to have players like Holt in the ranks to pass on valuable experience.
El Ahmadi said: "The new boys were excellent at Liverpool.
"Bertrand is a top player. His quality speaks for itself. He played in the Champions League final for Chelsea.
"Holt is very experienced and when he came on at Anfield he was very vocal and encouraging with the rest of the team, giving advice to the players on the pitch."