Sylla completed a £1.7 million move from Ligue 2 side Clermont Foot and made his Villa debut as a second-half substitute against Everton at Goodison Park at the weekend.
El Ahmadi made his return to the side in the 3-3 draw after being on African Nations Cup duty with Morocco and will thrive on the battle for a spot in the team.
He said: "It will be good for the team to have that competition. I think the new signings are players we need at this moment in time.
"Yacouba is a good player and what we need.
"From what I've seen so far in training, he is a very good player. He's a strong guy and that is something we need."