Form is a concern for the Cottagers with just two wins in their last 15 games.
Briggs told fulhamfc.com: "I think it's only a matter of time.
"It hasn't been easy, and when you break it down like that it isn't good enough. I do think we have been very unlucky at times, but that's football isn't it?
"Every side goes through bad patches, and that's what we have to deal with. We have a lot of quality though, and I'm sure it will click into place for us.
"We need to find our feet again, we need to find the momentum that we had before.
"There are positives to be taken despite the results, and we believe we can find our form again."