The trade was announced after Chicago's 5-4 shootout win over Phoenix on Thursday night.
The 27-year-old Versteeg, a member of the Blackhawks' 2010 Stanley Cup championship team, has two goals and five assists in 18 games this season with Florida.
Versteeg had 20 goals and 24 assists in 79 regular-season games with the Blackhawks in 2009-10, then added six goals and eight assists in 22 playoff games during the team's run to the Stanley Cup. He had a career-high 22 goals and 53 points with Chicago in 2008-09.
It's not just going to happen on its own. We have to have guys commit to the areas we need to improve on. We're going to be better than last year but there is still a long way to go. But I really like the pieces and where we're headed.
— Sabres forward Tyler Ennis on the progress of Buffalo's rebuilding process