Turner was on revocable waivers, so the Marlins could pull him back, however, since he was designated for assignment, pulling him back would mean they'd then place him on outright waivers. If that happened, the order would remain the same to claim Turner and only the Rockies would be in order before the Cubs. Basically, it seems pretty likely that the Cubs will flip a very minor prospect to the Marlins for Turner.
Some of the shine has come off Turner after his big-league struggles, as he is 4-7 with a 5.97 ERA and 1.65 WHIP. On the other hand, here's what I said about Turner yesterday: "Still, he's only 23 and last year had a 3.74 ERA in 20 starts. Also, a few advanced stats show he had pretty bad luck this season, such as a 4.01 FIP, 3.93 xFIP and .368 allowed batting average on balls in play."
Turner was the ninth overall pick in the 2009 draft and was the main component in the trade that landed the Tigers Anibal Sanchez and Omar Infante. He was once a top-15 prospect in all of baseball. Given that he's only 23, there's still plenty of time for him to achieve his promise.
The move for the Cubs seems a no-brainer, especially in light of their need to develop pitching and how well pitching coach Chris Bosio has worked with several others in the recent past, such as Jake Arrieta this season.