When Sunderland head to Wigan today for the first time since Steve Bruce swapped clubs in the summer, they could climb up to fifth and within two points of fourth place if they win.
It is a far cry from this time last season, when a fifth defeat in a row at home to Bolton left the Black Cats staring at the prospect of relegation, with Keane becoming increasingly frustrated.
It is 12 months ago this weekend since Sunderland lost 4-1 to Bolton at the Stadium of Light, with Keane deciding to walk away on December 4 after claiming he did not have the full support of owner Ellis Short.
Regardless of the relationship between Keane, Short and chairman Niall Quinn, however, it has since become clearer that the players have felt more content.
While McCartney, Keane's last signing when he made the £4.5m switch from West Ham on September 2 last year, was not directing criticism solely towards his former boss, the full-back's comments painted their own picture.
Around the place everyone is just that bit more relaxed.
They feel they can do things without probably having to answer to certain people,
The manager has come in and changed things around.
He's put his point of view across and everyone seems to have accepted it and been happy with how things are going.
Obviously he's (Bruce) made a few really good signings and they seemed to have benefited the team on the pitch. There is instant respect and affection for him because he is so laid back.
If you give him respect, he'll give it back and there is a human face there as well.
You want to work for him.
There was a feeling among supporters during Keane's final days that one of his biggest mistakes was trying to bring in controversial talents without taking time to consider their characters.
With that in mind it was no surprise when Ricky Sbragia, Keane's successor until the end of last season, opted to sell both El-Hadji Diouf and Pascal Chimbonda within six months of their arrivals.
Had the terms of the loan agreement with Marseille allowed it, Sbragia would also have sent Dijbril Cisse back.
At any football club you have little cliques. You're never going to get away from that but probably last year because we weren't so consistent those cliques became worse, said McCartney.
It's never a happy place to be when you're not winning as often as you'd like to and you're always around the bottom of the table.
Maybe last year the foreign lads who came in had a bit of an attitude about them.
I'm not saying that in a bad way necessarily it was just their way of doing things.
Certainly the lads I've seen this year John Mensah, Lorik Cana and Paulo Da Silva are good players but they're top men too and easy to get on with. Probably the younger lads in the squad don't feel so intimidated by them.
A major factor in Sunderland's start to life under Bruce has been the success his central midfield have enjoyed.
Whether it has been Cana, Cattermole, Jordan Henderson or Bolo Zenden, Sunderland have had workmanlike performances with an intention to push forward.
Having not known too much about Cana before his move from the South of France, McCartney now feels Bruce has pulled off a transfer masterstroke.
I was surprised that Marseille let him go. As a person he's one of the nicest guys you could meet.
He's down to earth, he's not got a chip on his shoulder and he's a really top bloke,
For £4.5m he was an absolute bargain and I'm really surprised none of the teams in the top four had a look at him.
Probably there weren't too many of our fans who had heard of him before he came to Sunderland. But what he has brought to us is incredible, on and off the pitch. It benefits anyone.