Social media was abuzz when the Pompey team was named an hour before kick-off.
A surprising team selection ensured home fans were frantically trying work out exactly who would play where.
Nathan Thompson was one of the wild cards, with the right-back thrust into a central midfield role against Scunthorpe.
And the summer signing impressed in his new position as the Blues secured a 1-1 draw with their fellow play-off chasers.
He said: “The manager mentioned it to me on Friday morning and that he thought it was important we had the three big lads at the back with the way Scunthorpe play.
“So I was needed to break up some of the attacks from their forward players and I do think it worked well.
"It’s not foreign to me and I believe that I’m capable of adapting to numerous positions in order to help the team out."
“I often played in a back three at my last club and when we went forward, I would step into that midfield role.
“So it’s not foreign to me and I believe that I’m capable of adapting to numerous positions in order to help the team out.
“You cover more ground in midfield, but don’t do it at such an explosive pace. It was a bit of a shock to the system!
“But we perhaps caught Scunthorpe off guard a bit because they would have worked on certain things and not expected the way we lined up.”
Jamal Lowe’s goal gave Pompey an early lead, only for Kevin van Veen to level for The Iron after the interval.
Thompson said: “Scunthorpe have been up there in those top places for the past couple of seasons.
“So although it’s disappointing that we couldn’t get the win – especially after taking the lead – it’s probably a good point on reflection.
“It was inevitable that they would come back into the game. They’re up there for a reason and do the basics very well.”