Record signing Bent was axed from the starting line-up against the Baggies, with Lambert preferring Gabriel Agbonlahor and Christian Benteke in his starting line-up. Bent was introduced midway through the second half and earned Villa a point with an 80th-minute close-range effort.
But, when asked if Bent was upset, Lambert said: "No, he was great. There was no problem. I just named the team and that's the team I picked."
The England striker admitted it has been a difficult couple of weeks having also lost his England spot and the Villa captaincy, to Ron Vlaar.
Lambert added: "Everyone is as important as anyone else. I explained the captaincy thing was to do what he did there - to score. That's the only reason I did it.
"I need everyone. If we can keep the collective thing and have the crowd with us, we'll be fine."
He said: "I thought the response was great, especially after playing 120 minutes on Tuesday. It was a big, big ask but the response was excellent."
Baggies boss Steve Clarke was disappointed to concede a late goal but hailed a top-drawer performance from Ben Foster. The former England goalkeeper bounced back from his poor performance against Liverpool in midweek with several fine saves.
"Having been in that position I'm a little bit disappointed we didn't go on and win it," Clarke said. "But Ben Foster was excellent. I said the other night when he made the mistakes there was nothing to worry about - and he proved that. He's a top goalkeeper and made one save in the first half off the deflected shot which was unbelievable."