Kerr was on the books at Fir Park this time last year and has seen a huge turnaround in their performances.
He told the Edinburgh Evening News: "I have seen a massive difference in Motherwell. They came to Easter Road the other week in the CIS Cup and they were different class that night. For the whole 90 minutes I thought they were quality, their passing and the fact that all of the players looked hungry. I think Mark McGhee has done a good job so far, they performed well against Rangers and probably deserved a win in that game as well.
"It is a similar squad with just one or two additions but he just seems to have given them that bit of confidence and belief in their own abilities. Some of the lads who probably weren't firing on all cylinders last season have come out of the blocks really well this time round and they really look the part this year.
"They have come on in leaps and bounds this season but they are in a similar position to us this season because they have a fairly small squad as well and a few injuries could really damage them. Teams outwith the Old Firm have to keep as many players as possible, free of injuries for as long as possible and see how far they can go."