No further details as to why assistant manager Ian Culverhouse and head of football operations Gary Karsa will not support the Scot for this weekend's clash with Southampton have been released.
Villa, who have lost their last four Premier League matches, find themselves just three four points clear of the relegation zone.
Lambert has replaced the pair on a temporary basis with former player Gordon Cowans and back-up goalkeeper Shay Given promoted to joint assistant manager roles.
And the 44-year-old is confident the pair can step-up ahead of Saturday's match at Villa Park.
"I'm delighted to have Gordon and Shay to assist me in preparing the team for Saturday which is what the whole group is focused on," Lambert told Villa's official website.
Given, who has not featured in the Premier League this season, admitted he was happy to be given the chance to assist Lambert.
"It's important that each and every one of us take responsibility right now and I'm delighted to play my part in helping the manager and the team go and try to win on Saturday," he said.
