Real Madrid striker Kylian Mbappe admitted his team was not consistent enough for a top eight spot, as his side slipped into the Champions League play-off round on Wednesday.

The record 15-time European champion fell to a 4-2 defeat at Jose Mourinho's Benfica, finishing ninth in the league phase table, meaning it must face the Portuguese side again or Bodo/Glimt in February instead of reaching the last 16 directly.

After three wins in its previous three matches under new coach Alvaro Arbeloa, Madrid was brought back down to earth by Benfica in Lisbon.

"The problem is we aren't consistent in our play, we have to fix that, you can't have one day (playing well) and another not, a champion team does not do that," Mbappe told reporters.

"We deserve to be in this situation today, Benfica were better, now we have to play two more playoff games. It hurts to have to play those, we wanted to have the time in February to work on our game."

Mbappe said he could not put his finger on a clear reason why Madrid played so poorly against Benfica.

"I think it's a bit of everything. I can't tell you it's just a matter of attitude, because if I only say that, you'll think we came here without any desire," said the French superstar, who scored twice in the defeat.

"If I tell you it's a football issue, you'll think the team is bad. No, I think it's a broader issue, and, in the Champions League, every detail matters if you want to beat your opponent.

"It shows you that, if you don't come in with everything you need to win a Champions League match, the opponent will come and, as they say, make fools of you."

However, Mbappe called on Madrid's fans to support the team at the Santiago Bernabeu on Sunday against Rayo Vallecano in La Liga, rather than booing as they did earlier in January.

"Come and support the team — we had a bad game — but we are not knocked out of the Champions League and in La Liga we're in a good dynamic now," pleaded Mbappe.

"If the Bernabeu is with us, we will win on Sunday."