With England already eliminated from Group D, manager Roy Hodgson made nine changes for their final outing against Costa Rica. However, rather than call on Celtic No.1 Forster to replace Joe Hart between the sticks, it was Foster who was selected and played the full 90 minutes.
"I need to say I was disappointed for Fraser that he didn't get the nod because, in my opinion, he is better than Ben Foster," Lennon said.
"Just being included in the squad was a fantastic achievement. He probably had the toughest test out of all the keepers available because he plays in Scotland. But he has spent the last two years performing in the Champions League and has been outstanding at that level.
"If you're asking me who is the second-best goalkeeper available to England, it is Fraser."