1. Milos Ninkovic (Sydney FC, midfielder)
He has been the front-runner since the start of the season.
His consistency, in a side that has lost only one out of 22 matches, has been marvellous and although his contributions of eight goals and 10 assists are enough to put him well in the frame on their own, he also does an enormous amount of running to try to win the ball and foil opposition build-ups.
Ninkovic has an advantage over several other main contenders in that he hasn't missed a game this season and has started in all of them.
2. Diego Castro (Perth Glory, midfielder)
Looks like he has the ball on a string and that always frustrates opponents.
Storming home over the second half of the season, the same as he did last year to pip Aaron Mooy on the post.
Castro has played in 20 games, starting 19 of those, and come up with nine goals and four assists.
He gets so much of the Glory's attack going and the quality of his passing so often puts the opposition under pressure to stop the moves from developing into goal-scoring opportunities.
3. Marco Rojas (Melbourne Victory, winger)
He has the best goals (11) and assists (10) total of any of the main contenders.
Rojas is very entertaining to watch as he runs the ball at defenders, who don't know whether he's going to cross it or try to cut inside and they often get bamboozled as a result.
He has won this award before and although he missed several games - he has played 19 and started in 18 - his contributions have often been so vital that he must be a big chance again.
4. James Troisi (Melbourne Victory, midfielder)
His form this season has won him a return to the Socceroos squad for critical 2018 FIFA World Cup qualifying matches later this month.
Troisi is such a busy player, who gets so many touches. Victory's attack accelerates when he becomes involved and he is equally adept at putting wide players, like Marco Rojas, into space or finding striker Besart Berisha in dangerous positions in and around the box.
Has played 20 games, starting in 19, for five goals and six assists.
5. Andrew Nabbout (Newcastle Jets, winger)
Six weeks ago you would have said he was in a battle for the lead, but Newcastle have slipped up recently and his own form has dipped as well, so that has got to hurt him.
But the points he would have built up before are still there and if he can lead a Jets revival over the last five rounds, he might still be in with a show.
Nabbout could never get a regular starting berth while he was at the Victory but given the opportunity at Newcastle, he has flourished - registering eight goals and four assists - in his 19 games (18 starts) this season.
Besart Berisha (Melbourne Victory, striker)
He is the competition's leading goal-scorer, with 17 in 22 games, and dominant strikers, including Shane Smeltz, have won this award before.
But votes for Victory players can only spread so far, with Marco Rojas and James Troisi well in the running.
Nicolas Martinez (Western Sydney Wanderers, midfielder)
He has been a stand-out in a side that has had an up-and-down season, appearing in 21 games (16 starts) and gathering three goals and four assists.
Martinez should poll well, but the Wanderers would probably need to storm home, in the closing rounds, for him to go close to winning it.
Danny Vukovic (Sydney FC, goalkeeper)
The trend with the Johnny Warren Medal, as with most awards of this nature, is that players who make and/or score goals get most of the recognition, rather than the ones who stop goals.
No goalkeeper has ever won it, so the in-form shot-stopper would have to make history.