Clarke, on loan from Wolverhampton Wanderers, scored the Latics' consolation goal in the second half.
Speaking to the club's official website, he said: “Obviously it’s great to get off to a goal scoring start, but the result is what matters the most, and with that we’ve been left disappointed. It’s bittersweet for me.
“It was nice to score, but I’d much rather be scoring goals that win us games. We’ve got to dust ourselves down and make sure that’s the case on Wednesday at Nottingham Forest.”
Clarke is in line to lead the line in Wednesday's visit to Nottingham Forest.