Hockey India has cracked the whip by slapping a two-year ban on star players Sandeep Singh and Sardara Singh for repeatedly indulging in indisciplinary activities.The national federation imposed the sanction on both the players after a marathon meeting in New Delhi today. The meeting was attended by the Hockey India top brass, including its secretary general Narinder Batra.The two players, who left the national camp in Bangalore reportedly after an argument with the coach, were also summoned to the meeting.Batra, however, said that both the players have right to appeal against the ban. The two players have been given 30 days time to lodge their protest.