A video of Amir Khan emerged on social media last night looking firmly unimpressed with the efforts of bitter rival Kell Brook as the latter labored to a unanimous points victory over Australian Michael Zerafa in their WBA super-welterweight title eliminator in Sheffield.Khan gives the camera a look of disdain as Brook struggles on the TV in the background, the first barb thrown in what will likely be a tumultuous period of negotiations in attempts to force the British stars to arrange a date in the ring.Brook has thus far resisted demands from the Khan camp for a 10lb rehydration limit in the 12 hours after weigh in.Such a stipulation would stop Brook from ballooning up in weight and would reduce the advantage such a weight gain would give him in the power stakes.The IBF insists on a 12-hour weight gain limit, and as no IBF belts would be on the line, Brook has felt justified in previously insisted that he would not give in to demands to regulate his preparations. Such justifications, however, will fall on deaf ears following an, at times, woeful performance last night against the unheralded Zerafa.Brook’s timing was often lacking and he appeared distinctly plodding on occasions.Despite a strong start from Brook, he allowed Zerafa to come back into the fight, and the latter was always in amongst the action, startling the favourite on several occasions with heavy shots.Such a performance from the former IBF welterweight champ will not trouble the other big names in the super-welterweight division.It is difficult to envisage the likes of Jarrett Hurd, Jermall Charlo or Jaime Munguia losing sleep over the prospect of fighting Brook on the back of such a performance, and all may opt to go elsewhere in their upcoming fights.As such, Brook’s options have significantly narrowed, and a big money fight against Khan, whatever the weight stipulations, may have become the best and most lucrative option on the table.Khan certainly didn't look too fearful as he watched on at home.

Brook came in light to last night’s fight with Zerafa, possibly in an attempt to show that he can still make the 147lb welterweight limit at which a fight with Khan would take place.

The 32-year-old weighed only 150.3lb at the weigh-in, giving up nearly 4lb on his opponent. Such a relatively low weight could account for the lack of power Brook brought to last night’s fight and may explain why he failed to put Zerafa away.

Unfortunately for Brook, such excuses are unlikely to wash with the boxing public, and a drawn-out negotiation with Khan’s team could see whatever appetite is left for the two to face each other promptly evaporate.