Fletcher admits to being disappointed at McCarthy's dismissal a week ago, after five and a half years in charge at Molineux, following the 5-1 defeat by West Brom.
Fletcher said: "It's football and the gaffer has been in it a long time. Now for him, and for us and all the fans we have to make sure we stay in the league and prove we are a good enough side. We know what our capabilities are and what we can do on the pitch and if we produce that we can stay up."
Wolves owner Steve Morgan and chief executive Jez Moxey are continuing interviews this week for McCarthy's successor with former Sunderland boss Steve Bruce favourite with the bookmakers.
Fletcher added: "It was a bit of a surprise (McCarthy's sacking) to be honest. We all came in on Monday morning thinking we were going to pick ourselves up after the Albion defeat and then heard the news.
"The gaffer brought me to the club after Burnley had been relegated and I've managed to score some goals since I've been here so it's a bit disappointing he's away."
Morgan and Moxey are still hopeful of having a new manager in place for Saturday's game at Newcastle.
On a personal level Fletcher is looking to build on his 10 goal tally which has already equalled his league haul for last season.
He said: "I remember saying at the start of the season when talking about targets that I wanted to get the same as last season or beat it.
"I've now got the same with 10 in the league and hopefully there's 13 games left now to try and beat it."
Source: PA
Source: PA