Southampton will seek an explanation from Ecuador's football federation after striker Agustin Delgado made a surprise comeback in the World Cup warm-up against South Africa.
Delgado has been plagued by knee problems that have prevented him playing a full match for five months.
He has been limited him to just 143 minutes of action for Southampton since his £3.5m capture from Mexican club Necaxa last November.
The 26-year-old arrived at Southampton with a knee problem that has needed two operations.
He was allowed by Saints to return to south America for a month to recuperate under the Ecuador team doctor.
Southampton then allowed Delgado to join up with the Ecuador squad for the friendly with South Africa in Alicante on the understanding he would not play.
But Southampton were surprised to discover that Ecuador coach Hernan Dario Gomez used Delgado for the whole second half of the goalless draw.
Gomez is desperate to have use of the talents of Delgado whose goals almost single-handedly propelled Ecuador to their first World Cup finals.
Delgado's record of 29 goals in 43 internationals for Ecuador dictates he carries a hefty goalscoring burden on his shoulders.
He was elevated to national cult status when scoring the winner in Ecuador's first win over Brazil in March 2001 and the coach was delighted with his performance on Wednesday.
"I'm happy because I saw Alex [Aguinaga] and Tin [Delgado] well and recovered," Gomez said.
"It is good to bring back two player who are very much part of my plans.
"We defended well and had dominated possession. Our touch was good, we passed well and were solid in defence."
The coach's thoughts now turn to a warm-up match on 1 May, in the Atahualpa stadium in Quito, against an as yet unnamed opposition.