Los Blancos are destined to finish the season in disappointing fashion after exiting the UEFA Champions League in the last 16 to Ajax and failing to keep up with the pace set by LaLiga leader Barcelona, which also dumped it out of the Copa del Rey.
Its season has been characterised by chaos in the dugout with the club burning through two head coaches – Julen Lopetegui and Santiago Solari – before Zinedine Zidane returned in March after resigning in the wake of leading the club to a third consecutive Champions League title in 2018.
Carvajal has featured 28 times in all competitions for Madrid this season but admits he is less than impressed with his contribution.
When asked by Marca what grade he would give himself out of 10, he said: "I'd give myself a four, a fail. I go with what the group is, and we've not done things well.
"It's football, but we haven't given the best we could give. For what reason, I couldn't tell you. But none of us have been at our best.
"We've been together for many years and we know each other. That has been the key, but this year we haven't fought for anything."
The 27-year-old pinpointed Madrid's failure to adequately replace their all-time leading goalscorer Cristiano Ronaldo, who joined Juventus ahead of the 2018-19 campaign in a €112million deal, as one of the main issues behind their struggles.
"It's clear that when a player hits 50 goals you have to try to find them from somewhere else," he explained.
"There have been times when we scored many goals, but also conceded. We had anxiety and it cost us points."