The club was coming off a spirited 2-2 draw with Manchester United at home, but failed to carry that momentum into the game on Tuesday.
Puel spoke with Sky Sports following the game and gave his thoughts.
"I think it was a tough game," Puel told Sky Sports.
"We needed to win the second ball. It is a story of free-kicks. They got two goals from free-kicks, and we have to correct this.
"Our first half was not bad. We showed quality and created chances. Then, we conceded a goal from this free-kick just before half-time.
"In the second half it was a little more difficult but they didn't create any chances. The result is a little harsh. It was not a bad game from us."