Grand National 2013: Imperial Commander heads Aintree entries Venue: Aintree Racecourse Date: 4-6 April 2013 First race: Thurs 4 April 14:00 BST Last race: Sat 6 April 17:40 The Grand National: Sat 6 April 16:15 Coverage: Commentary on BBC Radio 5 live or 5 live sports extra (also available online and on mobile devices). Saturday live text commentary on BBC Sport website The 2010 Cheltenham Gold Cup winner Imperial Commander heads 49 entries left in Saturday's Grand National at Aintree after the latest declarations. The 12-year-old is top weight and likely to run, with Sam Twiston-Davies riding for his trainer father Nigel. A maximum of 40 runners will line up for the National, with the final field confirmed on Thursday. On His Own, trained in Ireland by Willie Mullins, is the 7-1 favourite, ahead of Cappa Bleu and Seabass. Last year's Irish Grand National winner Lion Na Bearnai is out with an infection which has affected trainer Thomas Gibney's stable. Monday's other seven withdrawals were Prince De Beauchene, Bob Lingo, Tofino Bay, Bostons Angel, Beshabar, Wyck Hill and Magnanimity. On Thursday, the final line-up plus four reserves will be announced, with those getting in determined by their official rating. The Merseyside course was watered on Sunday as officials try to ensure safer, softer going, amid concerns over welfare. Two horses have suffered fatal injuries in each of the last two runnings and a new more flexible plastic core material has been introduced to fences in an effort to improve safety, The going on Sunday afternoon was described as good to soft, good in places.