The Blues drew 1-1 with Championship side Birmingham in a disappointing fifth-round FA Cup tie at Stamford Bridge on Saturday, with the pressure piling on the 34-year-old. Bolton, meanwhile, recorded a 2-0 victory away from home in their clash with Millwall.
Coyle's men face a trip to Chelsea next Saturday and the 45-year-old believes that despite the west London outfit's dip in form they will still have to be at their best.
He told reporters after the win against Millwall: "Whoever you play in the Barclays Premier League is top class. Chelsea away from home is a difficult game for anybody.
"If you asked somebody the question a couple of weeks ago when they were 3-0 up against Manchester United, that's how quickly football can change.
"The bottom line is when we go there we are going to have to be our best, but we've shown before we can get big results and big performances and that's what I expect us to be doing."
The Scot then moved to defend his opposite number's position, revealing he knows the former Porto boss well after doing coaching training with him while insisting Villas-Boas has a plan for the future.
When asked if he thinks the Portuguese will be in charge when they meet, he replied: "Absolutely. I know that's the nature of the job and given we're in the best league in the world, it's always somebody's turn one week or another but the bottom line is Andre Villas-Boas is a top class manager, and he's shown that. He's shown it from his grounding when he worked with Jose Mourinho.
"You can probably see and tell I'm a friend of his. We did a Pro license together and is somebody I got to know really well. He's someone I got on really well with.
"The bottom line is he's putting in place a plan that will serve Chelsea well for ages to come.
"We understand that the size of that club and the demands of it, they'll look for trophies each year but there's no doubt that will all come to fruition because he knows what he's doing and he's terrific at what he does.
"Yes, there's always going to be different times of form, it can be up and down, but for me there's no doubt he's the right man for the job and he'll show that to the be the case."
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