Lambert is likely to rotate his squad when Spurs visit Villa Park, with striker Christian Benteke almost certain to miss out.
Gabriel Agbonlahor and Antonio Luna could also be rested after returning from injury issues against the Canaries, with Lambert acknowledging his side's tough start to the season has taken its toll.
Lambert said: "We've played really hard teams in this opening spell - three teams you think will be round about there in Arsenal, Chelsea and Liverpool, and now we've got two more tough ones.
"The main one is Saturday but we'll do our best to get through the Tottenham tie."
Lambert selected a relatively strong side for the 3-0 win over Rotherham in the last round but is conscious of keeping his first-choice stars fresh with the City game approaching.
Other changes are expected to see Jed Steer once again replacing Brad Guzan in goal, while Nicklas Helenius and Yacouba Sylla could step into the starting-line up after being substitutes at the weekend.
Of particular concern to Lambert will be the fitness of Agbonlahor and Luna, who played against the Canaries despite only training for part of last week, and are unlikely to be risked again so soon.
Lambert added: "Gabby only trained for the latter part of the week, as did Antonio Luna. These are two big players for us, and they wanted to give it a go."