Porter singled it out as a key factor in the Under-19s' 1-0 victory against PSG in the UEFA Youth League.
Debutant Andre Harriman-Annous scored the match's only goal, and the team's staunch defense throughout the game ensured they maintained a clean sheet.
“Anyone watching that saw the sheer will and desire of the players to throw their bodies on the line and not concede and defend for vast periods,” Porter said.
“We actually played better in parts against Atalanta but conceded two set-piece goals.
“The boys worked really hard on that, we had honest reflections between us and today they had at least 15 corners and set-pieces which we defended impeccably.
“Watch our first team on set-pieces. They’re ruthless in one box and ruthless defending as well and they win games because of it.
“Andre was incredible and really took his opportunity. He can play multiple positions and scored a hat-trick on the weekend. For him to go again in a Tuesday game was tough for him but it was great to see how he approached it.
“Lucas only got back training in the last seven days. He broke his thumb in pre-season so he’s not played for a long time. He’s come over from Denmark and is adjusting but I had no doubt that it was a good opportunity to put him back in.
“The saves he made were incredible and he’ll only get better."