Latics boss Paul Jewell said: "Sun has paid his own fare over to England, so he is very keen to take his chance here.
"We'll just be looking at him in training this week and then we'll probably make a decision.
"Sun has had a long journey and it will take him time to recover, but he was recommended to us by an international agent and looks a good player.
"He plays mainly on the left of midfield and we'll just have to see how he shapes up.
"The squad is not too big on numbers and I'll be looking to bring some extra experience when the January transfer window opens, but overall I think we've got good quality here."
Jewell, meanwhile, has poured scorn on a Sunday newspaper article claiming Latics skipper Arjan de Zeeuw had said chairman Dave Whelan forced the players to endure a daily diet of jacket potatoes and beans in the club canteen and interferes on the training ground.
In the article, de Zeeuw was quoted as saying: "He (Whelan) is a control freak, he wants to make all the decisions.
"He walks in during training and interferes in everything.
"If he can, he will economise on everything and the food incident is typical. We are doing very well but we haven't even got a bonus for all our wins.
"He's really hard but he also has another side.
"When I was here in my first spell at the club, we played Gillingham in a play-off final.
"My dad was due to come over from Holland and I told him he was sitting in a
wheelchair and Whelan said, 'No problem, I'll fly him to the final'.
"He bought my father over, had him picked up in a fancy car and took him to lunch.
"It was great for both of us. That's Dave Whelan for you."
Jewell said: "We've had some fantastic press since the season started, collectively and individually, but you have to be very careful with the national media sometimes as it is very easy to be misrepresented.
"This time, they have set us up and maybe they are looking to put a spanner in the works.
"What was quoted in the newspaper was definitely not true and there is no problem between Arjan and the chairman.
"Arry has spoken to the chairman since and there's no problem at all. It's a big, bad world out there and you've got to be careful what you say and how you say it, because things can look different in print.
"Crucially, though, we want to portray the club well – we don't want it becoming a circus.
"Every time Wigan is mentioned in the media they want to talk about Uncle Joe's mintballs, pies or Wigan Pier.
"It is really good stuff for the Wigan Tourist Board, but the most important aspect for me is improving the club as we are not here to promote pies or whatever.
"But if we keep putting in the performances we've achieved so far, perhaps the national media will talk about our football.
"We will not allow inaccurate national newspaper reports to get in the way of what we are aiming for – Premiership survival.