Lambert may have impressed as Saints surrendered the lead to lose 3-2 against both Manchester United and City but his England dreams will rest heavily upon his ability to help Nigel Adkins' young team preserve their top-flight status.
"The lads are gutted," said Lambert. "There's no getting away from that. I felt confident we could hold out for at least a draw but it wasn't to be. We have to keep our heads up and take confidence from that form.
"Our performances haven't been worrying. We would have liked some points on the board but we're going to keep our spirits high and take confidence from it.
"We'll learn from it. That's twice now when we've been leading in games that we could have got something out of."