Coleman's own goal handed Bournemouth their 2-1 win on Saturday.
Harrison said: "As a team we are always trying to create own luck but we have been a bit unfortunate and today there were parts of the game we need to improve on. We need to do that moving forward and stay positive.
Advertisement
Advertisement
"It's tough for Seamus. He puts his heart and soul into this team and gives everything. It is always a difficult thing but Seamus is a great captain and great leader. He will bounce back.
"We just have to find a way to win. Our performances have been good but it's getting the results which are vital for us.
"Whatever happens off the pitch is out of control. We know as a team we have the quality to get out of a difficult situation."