And the 22-year-old believes Coventry can take heart from Barnsley's shock win over Chelsea in the competition last season.
Best, who wore a face mask to protect a fractured cheekbone, said: "Chelsea will be a massive game. To be playing against some of the best players in the world, you can only look forward to it.
"We can take encouragement from the fact Barnsley beat them in the FA Cup last season. Anything is possible in the cups and, if Chelsea come here and have an off day, we can take the game off them.
"I don't think there is really a danger of being overawed by them.
"We have got a lot of players who will giver 100 per cent no matter what and they will be looking forward to the bigger games rather than the little ones."
Best admitted: "That will be the biggest game I've played in along with Manchester United at Old Trafford in the Carling Cup - and we beat United. I am looking forward to it.
"It would mean so much to play at Wembley. As a footballer you dream about those things. It would be the equivalent of a normal person winning the lottery.
"We are not far away from the final now. We've got a game now against massive opposition but anything is possible."
Best is a Blues supporter and makes a point of watching them in action whenever possible on television.
He said: "I am a big fan of Didier Drogba and Nicolas Anelka. I think they are two of the best strikers in the world. Chelsea have got the best players.
"I never miss a Chelsea game if they are on TV. I'd always sit and watch it so I'm delighted to be playing against them.
"They have not been doing so well but they have got the quality. They could come here and be on top of their game. They did well against Aston Villa at the weekend but anything is possible."
Best would ideally like to complete a double by also helping Coventry to continue their recent good form and clinch a place in the Championship play-offs.
He said: "I think it is a possibility that we can get to Wembley and get in the play-offs. We have a few points to make up but the sky is the limit.
"We have still got a chance of promotion. It is a matter of getting the consistency against the bigger teams and I think we are doing well at the moment.
"We have not lost a game as long as I can remember."
Sky Blues boss Chris Coleman is also targeting a strong finish to the campaign in both competitions.
He said: "Why can't we have both, a real good end to the season all round? Why can't we do well in the league? We are eight points away from the play-offs and 10 or 11 points away from the bottom three.
"In the Championship, every game is winnable. It is not like the Premier League when you've got to go to Old Trafford or Anfield and it is very hard to get anything.
"In our league, and we have proved that, every game is winnable. If you can put a run together, and we are capable of that, two or three wins on the bounce, it changes your life.
"Whilst we are only seven or eight points away from the play-offs, and we have 13 games left, a lot is possible.
"We've got Chelsea in the quarter-finals of the cup and it is not impossible. That is not an impossible task. It is difficult and, of course, they will be the fancied team.
"They are a great team but it doesn't mean they are unbeatable."