Madrid: Spain striker Diego Costa is determined to repay the faith shown in him after he chose La Roja over his native Brazil and knows he still has a lot to prove after a stuttering start to his international career.
Costa made his Spain debut in a 1-0 friendly victory against Italy in March last year but did not open his account for the European champions until his seventh, and most recent, appearance, a 4-0 Euro 2016 qualifying win against Group C minnows Luxembourg in October.
The 26-year-old Chelsea forward has returned to the squad after a series of niggling injuries and will have another chance to show his worth if coach Vicente del Bosque deploys him in Spain`s qualifiers at home to pool leaders Slovakia on Saturday and away to Macedonia three days later.
"I never regretted choosing to play for Spain and I want to repay the confidence that has been shown in me," Costa told a news conference at Spain`s training base outside Madrid on Wednesday.
"I am feeling better physically all the time," he added. "I know I can give much more and hopefully that will start now."
With six matches played, Slovakia top Group C on a maximum 18 points after their surprise 2-1 over Spain in Zilina in October.
Chasing a third consecutive continental triumph, Spain have 15 points at second, with Ukraine a further three points behind at third.
Costa agreed with a reporter who suggested anxiety may be hindering his progress with the national team but said he was feeling more at home in the side all the time.
"It`s very important to me personally to perform well and score goals as that will give me confidence," he said.
"There are no excuses, I need to do better. I haven`t done anything yet and I think I can give a lot more.
"I am in a team with the current champions but I am feeling more comfortable all the time and closer to my team mates and that`s very important too."