The Baggies were contesting fourth place in the Premier League at the beginning of December but a poor run of results has seen them slump to ninth, and Clarke has admitted that they need to return to winning ways quickly.
Clarke told the Birmingham Mail: "Let's be honest, November was a really good month for us, December was average and January's been really poor, so I'm glad it's February and we can try and move on.
"The players have lost a little bit of confidence – that happens when you lose games.
"Some of the performances have been okay but we haven't got the results. It is time for us as a group of players, me and my staff, to get together with the players and rally round."
West Brom have not won a match since they recorded a 2-1 victory over Queens Park Rangers on Boxing Day.