Roberto Martinez said "maybe we needed it" after Belgium suffered a 2-1 defeat to Egypt in their final match before heading to Qatar for the World Cup.
Goals from Mostafa Mohamed and Trezeguet condemned Belgium to a second consecutive defeat, despite Lois Openda pulling a goal back late on in Kuwait.
Belgium are ranked second in the world but looked well off the pace on Friday and a shadow of the team that made it to the World Cup semi-finals in 2018.
However, Martinez is hoping the poor display and loss will shock his side into life, telling VTM after the match: "This was not the result or performance we wanted, but maybe we needed it.
"We showed that we are waiting for the World Cup to start, but not that we are ready.
"We're going to have to make sure every player is ready for what it takes. Because you can't go to a tournament like that and expect to perform if you're not at your best."
The defeat to Egypt, a side that did not qualify for the World Cup, comes just five days before Belgium's opening match against Canada.
Friday's encounter was also their first since a Nations League defeat to the Netherlands in September, while many of Martinez's players were still playing for their clubs just last weekend.
The head coach rued the lack of preparation time the fixture list afforded him, adding: "In principle you need about five weeks to get ready for the World Cup, but that is simply not possible."
Substitute Dries Mertens echoed Martinez's positivity, saying: "Losing is not ideal, but it is good that we played again. There is still work to be done, but it will be fine.
"It is better that this happens now than at the World Cup."
After the match with Canada, Belgium will then take on Morocco and Croatia in Group F.