THE battle of the bulge is threatening Robert Lui’s NRL career.

Nine months after sacrificing $1 million to stay at the Cowboys, Lui has been ordered to lose weight if he wants to continue his career in Townsville.

The 24-year-old showed incredible loyalty last year when he rejected a $1.2 million offer from the Warriors to sign a one-year, $180,000 deal with the Cowboys.

North Queensland were equally loyal, helping Lui through some off-field issues, but the club’s patience is being tested by the playmaker’s hot-and-cold form.

Lui took on Souths on Saturday night aware he is still a free agent for next season and his future at the Cowboys hinges as much on improving his consistency as his conditioning.

“Rob’s future is still up in the air,’’ his manager Mark Stewart said.

“We’ve had some preliminary talks with the Cowboys but they are waiting for Rob to really show them he wants to be there.

“He needs to work harder to drop a few kilos, which is what the Cowboys have asked for, so he's working on that.

“Hopefully over the next month Rob will improve his condition and secure his future at the club.’’

If there is an individual who sums up the riddle that is North Queensland, it is Lui.

At his best, the Townsville product seems the perfect scrumbase foil for Johnathan Thurston.

At his worst, Lui can be guilty of so many unforced errors he has had to endure intermittent stints in the Intrust Super Cup.

A man-of-the-match performance for Northern Pride a fortnight ago was evidence Lui is too good for second-tier football, but the Cowboys want more.

Lui, who scored two tries against the Knights last Monday night, has tentative interest from rival clubs but hopes to stay at the Cowboys.

“I just want to play good footy and let that do the talking,’’ he said. “I have re-signed for only one year but hopefully after this season I can sign a longer-term deal.

“The Cowboys showed me a lot of faith after the issues I went through and I want to prove I can be here for a long time.’’

Stewart denied speculation Canberra were targeting Lui and said his client’s move to five-eighth against Souths could aid his game.

“I haven’t spoken directly to Canberra,’’ Stewart said.

“There has been a little bit of interest in Rob but we haven’t talked figures with anyone.

“It will help Rob playing at six. At the Wests Tigers, his best football was at five-eighth.

“He was always better a little bit wider. That’s where he played most of his junior football, he was never really a halfback but Thurston moved to six so Rob was happy with the move.

“He was an absolute standout in the Queensland Cup the other week so Rob knows he needs to start delivering that consistently in the NRL.’’