Brown, Inu, Konrad Hurrell, Ben Henry and Carlos Tuimavave are options, and all but Inu have been included in the 22-man squad to face Souths this weekend. Inu will return to the squad to play Queensland Cup side Sunshine Coast at Whangarei's Toll Stadium on February 18.
McClennan will ask Vatuvei to play at centre against Souths to see what sort of impact he can make.
"We are looking at that option,'' McClennan said. "We'll give him a chance at centre _ possibly even at the trial on the weekend - and make sure we're giving everyone a chance of playing there.
"He came through [the junior grades] as a centre and did a good job there. We are serious about that option.''
Vatuvei is open to the suggestion.
"It would be good to try something new,'' he said. "I'm trying to get more involved in the game and take some of the workload off some of the big guys. As a junior I played in the forwards and centres before moving out to the wing. I am pretty comfortable there and happy to play wherever the coach wants me to.''
Ropati is the club's only established specialist centre but his 2011 season ended with a serious knee injury in round three against St George Illawarra.
McClennan said Ropati could be ready for the third warm-up game in Whangarei but it was a matter of being patient with his rehabilitation.
Rugby union convert Hurrell burst onto the league scene last year, scoring a try on debut for the Toyota Cup-winning under-20 side, and is shaping up as the most promising of the juniors. McClennan will give him a shot at centre this weekend, saying it will be a great experience for the 20-year-old to go up against a tough South Sydney unit.
Also included in the 22-man squad named to travel to Australia this week is prop Russell Packer and fullback Kevin Locke.
Packer and Locke missed the Warriors' first pre-season game last weekend, when they beat the Gold Coast Titans 26-10 at North Harbour Stadium.
Along with Ropati, Micheal Luck and Jacob Lillyman are also on the Warriors' injury list and will not travel.
Luck is recovering well from shoulder surgery but will miss the season opener against Manly at Eden Park on March 4.
Lillyman is facing three months on the sideline after tearing his right bicep from the tendon early in Saturday's match against the Titans. McClennan said the prop was philosophical about his injury.
"It's the sad part of the game, really,'' McClennan said. "There are joys and lows and unfortunately Bull got the low. Look at him last year, he played in the grand final and in State of Origin and now this. He's a good character, though, and knows that's the nature of the game.''
Sione Lousi, Steve Rapira and Ukuma Ta'ai are in line to replace Lillyman.
Warriors squad for the trial against South Sydney: Lewis Brown, Glen Fisiiahi, Nathan Friend, Pita Godinet, Ben Henry, Konrad Hurrell, Sebastine Ikahihifo, Shaun Johnson, Kevin Locke, Sione Lousi, James Maloney, Simon Mannering (c), Feleti Mateo, Ben Matulino, Russell Packer, Sam Rapira, Steve Rapira, Ukuma Ta'ai, Elijah Taylor, Carlos Tuimavave, Bill Tupou, Manu Vatuvei.
