"It's pretty simple: lose three in a row at the World Cup, and you need to win every game from now on in," Morris told reporters.
"But the guys know what needs to be done, they are disappointed and a little bit angry," he added.
"We'll sort that out in our heads tonight and when the sun comes up we'll go again.
"It's pretty simple: win the next six and crack on."
Morris made 42 in a meagre total of 227-9 following a top-order slump sparked by Jasprit Bumrah and continued by Yuvzendra Chahal.
Morris then bowled well but without much luck in a return of 1-36, as India cruised to victory on the back of Rohit Sharma's unbeaten 122.
"The schedule has been a bit tough," admitted Morris.
"Mentally we are pretty fresh, it's quite draining to go three down.
"But I think we'll be okay, there's a lot of strong-willed guys in that team."
He added: "The fans at home, all we can say to them is 'stay with us, back us as much as we can and we'll try and perform for you'".
With the Proteas back at Southampton to face the West Indies on Monday, Amla said he hoped they had learned some valuable lessons.
"Generally you learn more when you lose, although we would have loved to win," said Amla.
"We know how the wicket will play -- we anticipated it would be higher-scoring but it gave more assistance to the bowlers than we thought. It nipped right until the end, it wasn't a 300 type of wicket probably close to 250, 260."