Head coach Trevor Bayliss admits England have had a "reality check" ahead of next month's ICC World Twenty20.
Eoin Morgan's team finished their tour of South Africa with five straight defeats, three in 50-over cricket and two in T20s.
The worst was saved until last, as England were hammered by nine wickets at the Wanderers after their last seven wickets fell for 14 runs on the way to 171 all out. They were then powerless to stop AB de Villiers (71) and Hashim Amla (69no) cruising to the victory target.
De Villiers needed only 21 balls to race to his country's all-time fastest 50 in the sprint format - and from 27, Amla was no slouch either.
Bayliss' immediate response was that the contest was "men against boys".
Asked whether 'reality check' might be another appropriate term, he said: "Yes, certainly. It shows we've still got a lot of hard work to be done.
"We've had some good results, but it's a reminder to people back home in England that this team is still a developing one.
We've had some good performances, and there's a lot of potential there. But potential never won anything... we've got some hard work to do.
"I think the expectation the players have put on themselves is why they are so disappointed when they play badly. It may be that extra pressure they put on themselves that they've got to get over."
The Australian still believes that England are a team capable of surprising opponents once they get to India - including South Africa, whom they will face in a group match.
"We'd obviously be better off going to the World Twenty20 with a couple of wins under our belts," he added. "But in Twenty20, the momentum of games can change very quickly - and so can results.
"I don't think it really matters all that much. We're three weeks away yet from the first game and have a couple of practice games over there... we're looking forward to them."
Watch the ICC World T20, live on Sky Sports from March 8.