Garcia's side had won their opening 10 matches of the Serie A season to set a new record for the best start to an Italian league campaign but were stunned by Torino in a 1-1 draw last week.
While Roma were disappointed by the result, Garcia says he saw a resolve in his players in the rooms at the Stadio Olimpico di Torino to hit back against Sassuolo when they host the northern club on Sunday.
"I saw an angry team at the end of the Torino game," Garcia said on Friday.
"The guys are so keen to win that they were already thinking about Sassuolo after the match on Sunday.
"I was really pleased with how we did in the last few minutes at Torino. The players ran over to take throw-ins and played quickly without wasting time, to have a few extra minutes.
"This is a good sign for me as the coach and for the squad – I really liked this attitude."
While Garcia was understandably 'happy' with the Serie A standings heading into this weekend's matches - Roma lead by three points ahead of Napoli and Juventus - the French coach was not willing to talk about winning the title.
"The Scudetto candidates? I think all of the sides in the top half of the table have done very well so far," Garcia said.
"Juve and Napoli are the favourites and have squads built to play in both the Champions League and Serie A."
Garcia added injured attackers Mattia Destro and Gervinho are close to returning to the first team after time on the sidelines with knee and thigh injuries respectively.
"It's important that Destro is back training with the squad and I'm very happy about that," Roma's coach said.
"Now he needs to focus on his fitness and get a feel for the ball again.
"Luckily we now have the international break and he will have two weeks to work hard – I hope he can be back soon to help out the team.
"Gervinho is a lot better and he's now running on the field.
"We'll see how he is tomorrow and we'll try to have him in the squad for Sunday."
