The experienced midfielder has conceded that BVB could have lost their DFB Pokal semi-final had their opponents been more clinical
BVB beat Wolfsburg 2-0 at the Signal Iduna Park on Tuesday evening courtesy of first-half goals from Henrikh Mkhitaryan and Robert Lewandowski, but Dieter Hecking's side spurned a number of chances throughout the encounter.
Ivan Perisic had a goal disallowed and Junior Malanda hit the post before Lewandowski's opener, while Wolfsburg piled on the pressure late on, and Kehl has conceded that things could have gone differently had the guests converted one of their many chances.
"If you look at it objectively, you have to say that we were definitely lucky on one or two occasions," Kehl told the official Dortmund website.
"Wolfsburg created a lot of chances but for whatever reasons they were unable to score a goal.
"We have put in a lot of hard work in the last couple of weeks and deserve our place in the final."
Dortmund will meet either Bayern Munich or Kaiserlautern in the final in Berlin on May 17.
BVB last won the German cup in 2011-12, when they beat Bayern 5-2.