Second-half goals from Luis Diaz and Juan Cuadrado took Colombia to a 2-0 friendly win over Germany on Tuesday, deepening home coach Hansi Flick's woes a year out from Euro 2024.

Liverpool forward Diaz leapt high to head in a looping Cuadrado cross before the Juventus wing-back scored a late penalty after Germany captain Joshua Kimmich handballed in the box a minute after coming off the bench.

It was Colombia's first win over Germany and means the four-time world champions have won just one of five games since their disastrous group-stage exit at the Qatar World Cup in December.

Germany, who qualify for next year's Euro as hosts, lacked fluidity in Gelsenkirchen, ramping up the pressure on under-fire boss Flick, with the side not playing again until September.

"I'm very disappointed for the fans," said Flick. "We wanted to try something but it went belly up."

Flick was bullish on his side's long-term chances, saying his side would "show a different willingness, a difference performance" in the next round of friendlies. 

"From September, we'll settle in and then the results will come."

With isolated boos and whistles ringing out across his home-town stadium in Gelsenkirchen, local boy turned captain Ilkay Gundogan said he could "understand" the crowd's response. 

"We know it was not good and we know what needs to get better."

Asked if he was worried by the team's latest display, midfielder Leon Goretzka said: "I don't know if that's the right word."

"It's dramatic, you have to say that clearly... We're missing things across all levels. All in all it was far too little."

After making nine changes for the 1-0 loss to Poland in Warsaw on Friday, Flick again switched things up with five alterations in the starting XI.

The coach handed the armband to Gundogan after the treble-winning Manchester City captain's recent successes, with Kimmich starting from the bench.

But Germany again looked disjointed and were lucky to avoid conceding a penalty midway through the first half when the home side were caught out by a lightning-fast Colombia counter.

Centre-back Malick Thiaw, in just his second match for Germany, appeared to have brought down Diaz in the box but the referee ruled the AC Milan defender got a toe to the ball.

Diaz got on the scoresheet however in the second half, heading in Cuadrado's ball after Emre Can was dispossessed in his own half.

Flick brought Kimmich on for Gundogan with 10 minutes remaining and the Bayern Munich midfielder gave away a penalty moments afterwards.

Cuadrado stepped up to the spot to send Germany goalkeeper Marc-Andre ter Stegen the wrong way.

While Flick has repeatedly defended his side's results on the basis of a desire to experiment before Euro 2024, his position may now be called into question.

Germany play two home friendlies against Japan and World Cup runners-up France in September.