Bryan Oviedo remains fully committed to Sunderland after a deadline day move to West Bromwich Albion collapsed.
But the Costa Rican left-back admits his lack of game time for Sunderland is a concern when it comes to his international prospects.
Oviedo - who is battling with Denver Hume and Reece James for a place in the Sunderland side - had been expected to join the Baggies as they push for promotion straight back to the Premier League but the deal fell through and Oviedo returned to Wearside.
Opening up about the failed move, Oviedo told La Nacion: "It was very stressful and tiring, because I was told at 6pm that I should travel to Birmingham, so I did not hesitate.
“I signed the contract 20 minutes before the window closed.
"However, five minutes after 11pm [deadline] they informed me that it had not been possible to do it.
“Maybe at the time I was affected, but from the moment it did not go ahead, I had to keep working.
"Physically I feel very well, I am training to the maximum to be considered [for selection].
“When I have the opportunity to play, it is clear to me that I must do it in the best way.
"My challenge is to help Sunderland to climb into the Championship.”
Chairman Stewart Donald has previously emphatically rejected suggestions Sunderland were at blame for the collapse.
"We received an enquiry," Donald told the Roker Rapport podcast.
"I didn't think it was enough if I'm honest but we checked with the footballing people [at Sunderland] and they were happy with that.
"We said OK, West Brom wanted to do it. This was with plenty of time to get it done.
"Then lunchtime on deadline day, our focus is completely and utterly on ins.
"We left it to Bryan and West Brom and the paperwork never arrived. Why that didn't happen is down to West Brom and Bryan, not Sunderland.
"It would have been beneficial from a financial perspective but it won't change the fortunes of the club. The contribution to the wage we would had to have made, it was more about giving Bryan game time and putting him in the shop window with a view on next year.
"He's been an excellent pro and is an excellent pro, he gives us 100% commitment."
Oviedo admitted, however, his lack of game time could harm his international hopes. Costa Rica are managed by newly appointed Gustavo Matosas.
Oviedo added: "I have not thought much about leaving because I have another year left on my contract [after this season].
"We are happy here, it is difficult to be in League One, but if we go up it will be different.
"With Matosas we have not had the opportunity to speak.
"Obviously I’m very worried about my international place, knowing that I’m not playing worries me, I’d like to be at the highest level, but it’s not in my hands.
"I try to stay in good physical shape, here I am in a demanding league. There are strong teams and I trust that if they take me into account I will do my best."