The Hammers will welcome Rafa Benitez and his Chelsea side to Upton Park on Saturday, with the Blues still looking for their first win and first goals under their new interim boss.
West Ham were undone by another title-chasing outfit, Manchester United, in midweek, but Collins feels Sam Allardyce's side, who continue to occupy a top-half standing in the Premier League, have every reason to head into their latest fixture full of confidence.
"We were disappointed we didn't get anything out of the game against Manchester United," he said in the Evening Standard.
"I imagine some teams who have gone to Old Trafford and conceded an early goal as we did could have been beaten six or seven.
"The result didn't go our way but we still have a lot of confidence as we go into the game against Chelsea. I don't think it's a bad time to play them. Things don't seem to be quite right there at the moment, not as settled as in years gone by.
"They've drawn their last two games and I am sure if we play as well as we did during the week we can get a result in front of our own fans.
"Chelsea are in their league position for a good reason. It's going to be difficult for us and we will have to defend well but we can hit teams on the break."
Collins will enter the weekend in the knowledge that he is just one booking away from a ban, and the Wales international is aware that serving a suspension could force him behind James Tomkins and Winston Reid in the centre-half pecking order.
He added: "I was a bit lucky to avoid another yellow card at Old Trafford.
"There was a tackle in the first half and a handball after the break so I just need to be a bit careful this time. It was really good to be back in the team but there have been no complaints from me.
"I pulled my hamstring against Manchester City but the boys have been doing well - James and Winston have been great - so as long as the team are performing well, I'm happy just to be back here and getting another chance."