The Seagulls have already sealed the League One title while Saints are currently in the second automatic promotion spot, level on points with Huddersfield but with a game in hand.
Harding was one of five Saints players named in the division's team of the year last weekend, compared with just three from Brighton.
The left-back, who began his career with the Seagulls, admits his old club are worthy champions but says Southampton have suffered from being a bigger scalp.
"They have had a fantastic season and all credit to them. They have done really well and deserve to be where they are," he said.
"But it also shows that when people play Southampton maybe they think they have to step up that extra 10 or 20% making our games harder, which is something we have had to live with this season. Hopefully we can get over the finish line."
Source: PA
Source: PA