The Giallorossi coach insists a gluttony of mistakes allowed his team to crash out of the Coppa Italia at the last-four stage to Napoli on Wednesday
Jose Callejon, Gonzalo Higuain and Jorginho struck for the Partenopei in their 3-0 second-leg win on Wednesday, sealing a space in the final after the opener finished 3-2 in Roma's favour.
Garcia thinks that the tie slipped away from the Giallorossi due to the first leg at Stadio Olimpico, when they conceded twice after taking a dominant lead, and he rued their missed chances in the first 45 minutes at the Stadio San Paolo.
"Perhaps we lost the qualification in the first leg, as we conceded two goals when we were 2-0 up," the coach told reporters.
"This evening we had three chances to score in the first half and didn't make the most of them. We should've been more ruthless in attack and also in defence, as we made mistakes in both legs.
"If there was a side that should've been in front at half-time, then it was us. The fact we weren't was our fault."
Garcia went on to congratulate Napoli for reaching the final, where they will play Fiorentina later this season, but insisted his second-placed Serie A side would bounce back from the loss.
"I congratulate Napoli, they have a strong attack and I wish them all the best for the final," the 49-year-old added.
"As for Roma, we've got to think positive because we do create chances in every game. The key to the future is to be more effective up front.
"Now we close the Coppa Italia book and re-open the Serie A one. We've got to win our next game against Sampdoria.