Well its very difficult to select Sachin Tendulkar (or for that matter any other modern great like Ponting, Kallis or Lara) in a all time world XI. Look at who Sachin is competing against for a middle order slot :
1. Don Bradman - unquestionably the greatest batsman ever 2. Garry Sobers - undobtedly the greatest all rounder ever (8032 runs @ 57.78 and 235 wickets in 93 tests) 3. Viv Richards - the most agressive batsman the world has ever seen (had 90 plus strike rate in limited overs cricket in 70s and 80s when 4 runs per over was considered outstanding). Also, one of the finest players of fastbowling and one of the hardest to dismiss. These 3 would easily walk into anybody's all time world XI. The only modern day great cricketer who can walk into an all time world XI is probably Kallis - that too largely because of his all round abilities