Bunn has made just five appearances for the side this season but seems to have gained the trust of manager Remi Garde, with Bunn's recent promotion to the side coinciding with some better defensive displays, and a small improvement in the club's results.
Guzan had been the club's number one goalkeeper for some time but things seemingly had to change at the back and the American has been relegated to the bench.
However, James doesn't believe that means that Guzan is responsible for the club's position, citing the goals Villa conceded in the 4-0 defeat to Manchester City in the FA Cup at the weekend by way of an example.
James told HITC Sport: "When your side is conceding goals, inevitably, some of them are going to be the goalkeeper's fault and when you're consistently conceding goals then your opinion swings towards the goalkeeper being at fault for these goals.
"Watching the highlights (of the Manchester City cup tie) of Brad pulling off saves and rebounds falling to centre forwards and it's a goal, you look at it and think 'this isn't his fault'.
"Simply looking at results, there has been an improvement (with Bunn).
"There might be different areas; distribution, dealing with crosses that can make confidence slightly brittle. I know having played in sides where things have gone well and things haven't gone so well, in the same side that is, and having remarks from defenders who say 'well, you used to do this and we love it and then you stopped doing it and we didn't know, what's happening?'
"Maybe that's the situation Aston Villa are facing at the moment. Again, Bunn has come in and rectified that area but I would not blame Brad Guzan for Aston Villa's position at the moment."
Bunn has managed to keep two clean sheets in recent weeks, and their past three Premier League results suggest they are steadily becoming a harder team to break down, but that will need to be the case between now and the end of the season.
It will be interesting to see over the next few games whether Bunn has had a positive effect on the defence, perhaps a more calming influence on the Villa side, providing that bit more certainty could be a building block for the rest of the side to improve their fortunes between now and the end of the season.
‘Watch West Ham United vs Aston Villa in the Barclays Premier League live on BT Sport 1 from 7:45pm on Tuesday 2 February. Visit btsport.com’