Wednesday prop up the Championship table and are winless from their opening eight Championship games.
They have taken a paltry two points from an available 24 ahead of Friday night's home game with Sunderland to heighten the pressure on Munoz, who has been criticised by fans for not only a lack of results, but also a perceived lack of identity in playing style.
Matters came to a head in last weekend's 3-0 loss at Swansea, which saw Wednesdayiyes chant for the dismissal of the Spaniard.
Bannan said: "I would not say it's anything to do with the style of play. There's a lot of people speaking about style of play and the manager, but as players, we have got to take the brunt as we are the ones out there and under-performing as a team and individuals.
"I know the manager is getting a lot of heat, but players tend to get away with it a lot of times. I think we have got to stand up in that changing room as well and take it on our shoulders.
"We have not performed as a team this season and it has let the manager and the club down this season and we need to look at ourselves before we look at anywhere else.
"We have had the manager for eight or nine weeks now and know what we want to do and what Xisco wants to do.
"There's been a lot of changes here and you can see it with other clubs who did really well last season are probably struggling a little bit this season which is down to a lot of changes - Middlesbrough, Swansea have started quite slowly and Coventry have lost a lot of players and had to bring players in.
"It does take time, but we have enough in that changing room to be better than we are doing. We are clear as to what the manager wants us to do."
Many sections of the club's fanbase are becoming increasingly disgruntled at not just events on the pitch, but off it.
A protest against chairman Dejphon Chansiri saw fans threw tennis balls onto the pitch at Hillsborough in the 15th minute of the recent home game against Boro.
A ‘black balloon’ protest is being planned online during Friday's match.
On protests, Bannan added: "We tend not to get involved in that side of it. It obviously wasn't ideal in the Middlesbrough game because we had a good start and Middlesbrough changed their tactics when the game stopped.
"Listen, that's nothing to do with us. We are players on that pitch looking to get a result. Whatever is going on around and outside the football club is secondary to us."
Urging fans to stick with the team, he continued: "Of course, as a fan you want your team to win and when you keep losing, the easiest thing to do is turn against the team. This is when we need the fans the most.
"You saw how powerful that crowd was in the second leg against Peterborough - without them we probably could not have done it.
"With the state we are in now, we need them even moreso now.
"Of course, I get their frustrations. Performances and results haven't been what we want. This is when we need them more than ever. It's a call from me and the players for them to try and push us on.