Sylla was signed from Ligue 2 side Clermont Foot and Dawkins was signed on loan from Tottenham, and Lambert insists the pair will be thrown straight into first-team action.
"The two of them are ready to go," Lambert told reporters ahead of Saturday's trip to Everton. "The lad Sylla will come in and will give us something we don't have with a bit of steel. He'll give us something in the middle of the pitch we haven't got. He will get stuck right in and you need players to do the dirty work."
Dawkins had been on loan for the last two seasons with the MLS Supporters' Shield-winning San Jose Earthquakes. He scored eight goals in 27 appearances in 2012 and six goals in 26 games in 2011.
"Simon can play anywhere. He will surprise people with the way he plays the game. He will create and make things happen," Lambert said. "He can play anywhere across the middle. He had a spell in America where he has been incredible. He's been in great form."
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