The Latics face competition from Boca Juniors, which own 50 per cent of Boselli's registration.
"There is long-standing interest in Boselli from many parties, from around Europe and in South America," agent Barry McIntosh told skysports.com.
"It is true that Wigan are now pressing ahead with their interest and are bidding close to the $10million (£6.9m) that Estudiantes are ideally looking for.
"But there is also Boca, and their new coach I know likes him a lot and they cannot be underestimated as they are still a very big club."
Asked about potential other suitors, McIntosh confirmed that Birmingham were one of a number of clubs who maintained an interest.
He added: "Birmingham have always liked him, as have other clubs in the Premier League, but things are progressing now and I can see something being done as early as next week."