South Africa were knocked out in the round of 16 by Cameroon after a 2-1 defeat at the Al Medina Stadium in Rabat on Sunday night.
Despite creating several chances that could have given Bafana the lead, Foster admitted the team fell short and said the focus must now shift back to searching for answers.
"It's tough to take because we had chances we could've converted, but we were just a bit unlucky. We should've taken the lead early and the way the game went after that wasn't the best. We'll just try and regroup now."
Foster believes Bafana were the better team, at least for the first 10 minutes when Relebohile Mofokeng and Samukele Kabini fluffed clear cut opportunities.
"We started the game really well, we surprised them tactically, and to be honest, we were the better team."
The Burnley forward admits Bafana were unsettled by The Indomitable Lions taking the lead on the stroke of halftime.
Foster also found it difficult in the moment to look ahead, but Bafana do have the FIFA World Cup as their next assignment.
"This is not the result we wanted, everyone is disappointed and we probably just need to process this as a team and come back stronger in March and then in June for the World Cup."