The general manager was disappointed with the Bianconeri's unbeaten run coming to an end at 49 games, and said that with an extra forward things may have been different
The Bianconeri scored inside 19 seconds thanks to Arturo Vidal's controversial opener, but Andrea Stramaccioni's men hit back in the second half thanks to a double from Diego Milito and Rodrigo Palacio's late strike to end the match in the visitors' favour.
The general manager entertained the possibility that the result might have been different had the hosts possessed a better goal threat in their ranks, but insisted that the side were not at their best.
"Was our attack light? Yes, maybe with a more clinical striker we might've had a different result," the 57-year-old told Tuttosport.
"We knew that [Inter] are among the contenders for the Scudetto, but we were not at our best. We were not able to maintain our intensity and we missed out on too many counterattacks.
Marotta then reflected on the decision to sanction the Chilean midfielder's first goal, before admitting that Juve's participation in the Champions League is proving to be an added burden on the club's fortunes this season.
"Maybe we're paying - more than others - a price for the high number of matches played this season," he added.
"Was our goal affected by an offside? The phase of play was quick and the linesman was probably not positioned perfectly."
Juventus resume their European campaign against Nordsjaelland in midweek, as they strive to pick up a first win on the continent in 2012-13.