"It was a typical pre-season match," he told the official site. "The two teams both worked hard and both sides had opportunities to score. I thought we played better in the first 30 minutes of the first half.
"Porto are champions of Europe and a very good team and like to play quick attacking football.
"We wanted to try a few things and in pre-season it was always my intention to make six changes at half time.
"I wanted to give the other players a chance and try different things and get to know them better."