Ten-man Rochdale held Southend United to a goalless draw at Roots Hall on Saturday afternoon.Dale had skipper Ian Henderson sent off five minutes into the second half for a late challenge on Stephen Hendrie.But the Shrimpers - who missed a first-half penalty when Simon Cox was denied by Brendan Moore - were unable to make a breakthrough.Rochdale threatened first in the opening exchanges with Jordan Williams having a powerful left-footed shot tipped onto the left post by Southend goalkeeper Mark Oxley.The Shrimpers' wasted an even clearer chance just before the break when referee Tim Robinson pointed to the spot after Joseph Rafferty had fouled Ryan Leonard.But Cox's low effort was saved down to his right-hand side by Moore.The referee angered Rochdale again in the 50th minute when he showed Henderson the red card for a challenge on Hendrie.However, Southend were unable to make a breakthrough despite Nile Ranger coming off the bench for his first appearance since being released from prison - after admitting to online banking fraud - last month.