However, he knows his former club will not be easy opponents for the high-flying Rojiblancos.
Atletico saw their 100 per cent home record this season ended by a 1-0 defeat to Sociedad, and that loss also cost Diego Simeone's men second place in the standings with arch rivals Real Madrid leapfrogging above them with victory at Celta Vigo.
However, Garcia says Atletico are optimistic they can get back on track against an Osasuna side who are just above the relegation zone.
"There's no reason for us to lose our heads, it was the first time we had lost at home all season and that means that we are doing things well," he said.
"The team are relaxed and we go to Pamplona confident we'll be able to win."
Sunday's match will be a special one for Garcia as he was born in Pamplona and began his career with the Navarran side before joining Atletico in 2007.
He also spent last season on loan there before returning to the Spanish capital, so he knows just what Atletico can expect this weekend.
"Something strange was happening to them at the start of the season, they seemed more comfortable playing away than at home, but things have changed now, they have signed some good players and recovered well. It won't be an easy game at all," the 26-year-old told reporters.
"Everyone knows that their fans help their team a lot in their stadium. They have launched a campaign to fill their stadium for the last few matches, I'm sure the pressure there is going to be the same as always."
He added of his return to Pamplona: "When the fixture list came out the first thing I looked for was when I was going to return [for the match at Osasuna]. Of course I want to play in the game, it means a lot to me, it's a date I have marked out."
Osasuna assistant coach Alfredo Sanchez, taking over media duties from Jose Luis Mendilibar with the coach having suffered a family bereavement, believes that Atletico will be even more determined to win on Sunday after surrendering their top-two spot to Real.
He said: "Perhaps they'll be even more alert alter losing second place, and they might be more dangerous when they are wounded. They are an aggressive team, they are very compact, rock solid in defence and they have creative forwards who can cause a lot of danger."
Diego Godin will be absent for Atletico Madrid due to suspension, while Osasuna's Francisco Silva is also banned following his red card against Real Betis last Friday.