The midfielder has been linked with AC Milan.
“Jankto won't leave in January and we've said so several times," Gerolin told Sportitalia.
“We want to keep our players until the summer because we're in an interesting position in the table.
“At the end of the season, we'll see what can be done, but we want to nurture our young players this season.
“We've received a lot of offers in Udine, it's true, but our policy has always been the same and everyone knows that we want to finish the season with a group of players that can make the fans happy and maybe finish in a certain position, which we haven't been able to for a couple of years.
“After that, before giving up our jewels, we have to find suitable replacements so we don't get any weaker."