Oxford United boss Darren Patterson says he will clamp down on any player who shows a lack of discipline after a catalogue of cards in their FA Cup replay defeat at Southend.

As well as losing the game 3-0, the U's had six players booked and the number of yellow and red cards is proving costly.

Clubs who have five players yellow-carded in one game are fined £750 by the Football Association, and the accumulation of bookings is also leading to suspensions.

Billy Turley, who was cautioned for bringing down Dean Morgan, which earned Southend their first penalty, has now collected five yellow cards.

He is suspended for the Setanta Shield fourth-round tie at Aldershot on December 22, unless the FA Trophy tie against Tonbridge Angels on Saturday goes to a replay, which would be next Tuesday.

Oxford did not have a single player red-carded under Jim Smith this season.

Yet they have had a player sent off in each of the first three league games under Patterson - Rob Duffy, Carl Pettefer and Alex Jeannin - although all three seemed harsh decisions.

The six players booked at Roots Hall on Tuesday night were Luke Foster, Joel Ledgister, Eddie Hutchinson, Ashley Barnes and James Clarke, plus Turley.

Patterson was not over-concerned about Turley's forthcoming suspension, but he is alarmed by some unprofessional or unnecessary bookings.

"If Billy is going to miss a game, the Setanta Shield is the one we'd want him to miss, I've got to be honest with you," he said.

"The only negative thing - and it's not a big one - is that there's a little bit of indiscipline coming in with some of the bookings and I'm going to come down very heavily on them.

"Whilst we've had sendings-off which have been very unfair, from bad referees, I'm not going to tolerate indiscipline."