United States goalkeeper Brad Guzan has held the number one spot at Villa Park for the best part of two seasons, starting in all bar two top-flight matches.
Former Republic of Ireland custodian Shay Given replaced Guzan for those two games, but they were his only league starts since featuring 32 times for Villa in the 2011-12 season.
Given went on loan to Middlesbrough last season and despite Guzan's apparent hold on the number one role, Lambert refused to reveal who would start when Villa's league campaign begins at the Britannia Stadium on August 16.
"I've got two really top goalkeepers in Shay and Brad," Lambert said.
"They will push each other and come the Stoke game I will pick the strongest team."
Guzan, who travelled to Brazil with the US World Cup squad, was at fault for two goals in Villa's 3-1 friendly defeat at League One new boys Chesterfield.
But Lambert was not worried by the former Chivas USA man's blunders.
"I said to him he better get them out (the errors) before the start of the season," Lambert said light-heartedly.
"On a serious note, though, he only joined up with us in Houston and has not done much before that.
"The two years I have been here he's been absolutely brilliant.
"He can make as many mistakes as he likes in pre-season games but when it's for real I'm sure he'll be right up for it."
Guzan and Netherlands defender Ron Vlaar were Villa's two representatives in Brazil and Lambert does not expect the duo to find it difficult to get motivated for the new season after the experience of playing on the biggest stage of all.
"I don't think it's a comedown for them," Lambert said.
"Once the league starts the adrenaline will take care of that. They will be totally fine.
"They've not had much rest and they've got to go again now but once it starts for real they will be totally fine."
