With NBA players returning for real next Friday, there will only be about two weeks of training camp before the regular season is scheduled to tip-off on Christmas Day with the Celtics playing the Knicks. The NBA is expected to announce its full schedule next week, but the Celtics announced their two preseason games will be played on Sunday, Dec. 18 at Toronto at 1 p.m. and on Wednesday, Dec. 21 at TD Garden against the Raptors at 7:30 p.m. Tickets for the preseason game, as well as regular season games will go on sale in the week of Dec. 12. For more Celtics news, visit the team page at weei.com/celtics.