The striker, who joined this month from Birmingham, netted just 116 seconds into the opening pre-season friendly of the summer, as Saints drew 1-1 with SCR Altach at the end of their week-long training camp in Austria.
The forward would later hit the post and be denied another time when through, before he was withdrawn along with the rest of the first-half team at the interval.
"Ché could have scored three times, I think," said Hasenhüttl. "He was a little bit unlucky, but he made the first goal, which was important for him.
"He showed from the first moment on that he can help us next season, and I'm happy that he is with us."