Whether it’s the a surge of adrenaline from having all of their players back in practice for the first time in a long while or the promise of a new calendar year, the Bulls are brimming with optimism these days. “It’s great, great. Good to have everyone out there. Just get ready for the next game,” Bulls head coach Tom Thibodeau said after the team’s morning shootaround Thursday at the United Center. “I’m looking at our team and I like the possibilities. I love our team. I like the fact we have everyone back now and we have to work. I’m excited about that.” Bulls’ All-Star center Joakim Noah chimed in: “I think it’s great. We’ve just got to keep grinding, a lot of basketball left and I think that if we just keep grinding, keep our minds into it, it could be a hell of a year.” Heading into Thursday night’s home game against the Celtics, the 12-18 squad, even coming off a disappointing loss, sees a light at the end of the tunnel. Some of that is due to the sad state of affairs in the Eastern Conference, which features two elite teams in Miami and Indiana and just one more team — Atlanta, which lost its best player, big man Al Horford, to a season-ending pectoral injury — over .500.