Albion target Valentin Barco has seen his Copa Libertadores dream put under threat.

Barco wants to help Boca Juniors win South America’s most prestigious club knockout before moving on.

Progress through the quarter-finals would mean they were still involved in the Libertadores when the current transfer window closes.

But Boca were held 0-0 at home by Argentinean rivals Racing in the first leg last night and Barco went off with what has now been confirmed as a hip muscle injury.

It was an evening with underlined the 19-year-old’s huge promise.

He was a big threat down the left in tandem with Frank Fabra but went off early in the second half.

Barco asked to be substituted while holding his head in disappointment and early expectations are he will miss the return fixture.

The game changed after his exit with Boca losing command of proceedings.

Now they need a win on the road next Wednesday.

Defeat could possibly speed up Barco’s exit – with Manchester City also reportedly interested in his services.