The Latics finished fifth in the Championship in the 2013/14 campaign, but failed to get past Queens Park Rangers in the play-off semi-finals.
The 2013 FA Cup winners will be aiming for Premier League promotion in the upcoming season, and manager Uwe Rosler has identified the need for a forward.
The 45-year-old German boss met with Whelan in Majorca to discuss which players to sign this summer transfer window.
"We've been chatting about next season, and I have to say things are really taking shape," Whelan told the Wigan Evening Post.
"Uwe's looking to bring in a striker, and he thinks he’s got one. We're looking to bring in three or four players in total. That should do us for the new season."