Scouts from both clubs were at Wolves’ 1-0 Championship home win over Rotherham.
But the Portuguese ace, 23, was unable to add to his 10-goal tally in all competitions. He had a first half penalty saved and was subbed in the 66 minute.
Wolves signed Costa permanently in January for a club record £13million after he impressed on loan from Benfica.
Costa shot to prominence earlier this season with a thrilling display when Wolves won 2-1 at top-flight Liverpool in the FA Cup in January.