Blades manager Kevin Blackwell said: "It's great to have him back and nice to see him here with a bright, bubbly smile which has lit the place up.
"But the ban hit him hard and it must be a great weight off his shoulders for it to be almost over.
"It hit everybody out of the blue just before the start of this season and I hope that it will be a lesson learned for everyone."
Blackwell, who warned Kenny may not appear in the first team this season, added: "A year is a long time to be out and we'll try and arrange two or three behind-closed-doors games for him just in case we have to call on him. Steve Simonsen is here for a month anyway and we will monitor the situation."