They will take on the Iron over two legs in the play-off semi-finals, with the winner facing Leeds United or Millwall at Wembley.
"We had many games in March which cost us, but once we got that behind us, April was a better month for us," Di Matteo told Sky Sports News.
"The players have given everything and worked very hard. We have a very good group of players and I think we have a good chance in the play-offs."