But the 27-year-old has since proved to be a shrewd acquisition with some inspirational performances at the heart of the defence, including a man-of-the-match display in the goalless draw at Sheffield Wednesday on Saturday.
Clough said: "We needed a commanding centre-half and we are still of the opinion that had Shaun played all season we would be halfway up the league now, that is how important he is to us," said Clough. "Unfortunately, he missed a few games and we lost some of those games.
"You are only talking about one or two wins in that time when we missed him and we would be on 50 points and safe now. I thought he was outstanding against Wednesday, not just his heading of the first ball but his reading of the second one as well.
"The odd time Russell Anderson got beaten in the air, Shaun read it extremely well and covered. Once again, he looked a very promising centre half."