Colin Tizzard remains optimistic multiple Grade One winner Thistlecrack will be back in time to resume his racing career at Christmas.The nine-year-old was ruled out of the Cheltenham Gold Cup after sustaining a tendon injury in the build-up to the Festival showpiece, for which he was the ante-post favourite.After landing last year's Stayers' Hurdle, the John and Heather Snook-owned gelding had made a seamless transition to fences, winning his first four starts, including victory in the King George VI Chase, before tasting defeat to the ill-fated Many Clouds at Cheltenham in January.Tizzard said: "We've got to make sure we get him right for next season. The issue is only very small. We are in the middle of March now, though, and next season is not far away."Nature cures everything and we could help nature along a bit. The swelling has gone down and we trotted him out the other morning and he was sound."Racehorses that are big like him, there is a lot of strain on tendons. I see no reason at the minute why he shouldn't be back before Christmas and then have a couple of runs before the Gold Cup."