The attacking midfielder had to play out the final ten minutes of the game in net as goalkeeper Marko Marosi was sent off for handling the ball outside of his area.
McCann said afterwards: "We’re creating the chances but the goals haven’t been there today, don’t panic because they will come.
"I’m disappointed that we couldn’t do it for the fans today, they were fantastic throughout the game and I’m glad they showed the appreciation for the team at the end.
"The red card isn’t something you prepare for, credit must go to Ben Whiteman for stepping up and going on goal.
"We set up to play in a certain way, Portsmouth will come away from here happy with a point, their keeper has made some good saves, we just need to find that scoring touch and turn the chances in to goals now.
"The midfield were outstanding once again today, there’s really competition for places and players may have to bide their time before they break into the side.
"The performance levels are the key, I’m pleased with most of the group, the lads have performed really well so far so I’m happy with the squad."