Striker Diouf was rested for the weekend draw at Wolves, while midfielder Austin had only returned from international duty with Jamaica on Friday.
Manager Neil Warnock has hinted both new signings Steve Morison and Stephen Warnock are likely to continue after they made their debuts on Saturday.
Defender Warnock played the full 90 minutes at left-back, while Morison, back from a thigh injury, also completed the full match alongside Ross McCormack up front.
Boss Warnock, who has no new injury or suspension worries, is hoping to extend Everton midfielder Ross Barkley's loan spell at Elland Road this week as he is due to return to his parent club after the Middlesbrough game. The teenager was not involved at Wolves, but could return to contention.
Leeds hope to close the gap on the top six to two points with victory.