Lambert's side have lost their last two games 4-1 to Stoke and Manchester United to leave them 12th in the table and six points behind the 10th-placed Potters.
They suffered a further blow this week with the news that striker Christian Benteke will miss the rest of the season with an Achilles tendon injury.
However, Villa face bottom club Fulham this weekend and Lambert is adamant his team should be looking up the table.
"To be ambitious you've always got to look at what's above you to try to catch the teams ahead," he told the official Villa website.
"There's not much in that little group there with West Ham and Stoke.
"I also know it's a tough, tough league and you have to be right on it to get a result. Saturday's game will be no different."
During his playing days, Lambert represented Borussia Dortmund and is fully aware of the managerial capabilities of Fulham's German boss Felix Magath.
"His teams are always hard-working sides. I think if anyone knows his sides, he wants people to put an honest day's work in," added the Scot.
"I know the way his teams work. I played against Stuttgart when he was manager there.
"He might not have Premier League experience but he's coached some really big clubs in a really big league so he'll know how to handle it.
"To be fair to Fulham, I watched them the other day and they are still a really good side."