Roberto Martinez’s side, including Cristiano Ronaldo and fellow Wolves teammates Pedro Neto and Nelson Semedo were having their first run out in Gütersloh in front of almost 8,000 fans
But the session was ended early after a dozen supporters stormed the pitch.
Security staff helped prevent the vast majority from getting close to the Portugal players.
But one fan broke free of the pack before Sa took matters into his own hands.
Wolves’ number one rushed over to the touchline, dragged the offender around the neck and off the pitch.