If we've learned anything this season, it's that no lead on the PGA TOUR is safe. Troy Matteson is three clear of the pack at 18 under but still has one round to go on a course that will allow his pursuers to get very aggressive. Steve Stricker (-15) will join Matteson in the final pairing, looking to win his fourth consecutive John Deere Classic. Ahead of them, and at 14 under, will be Zach Johnson and Brian Harman. But there are plenty more players who could get into the mix. After 54 holes at TPC Deere Run, there were 26 players at 10 under or better. Here’s a look at some players outside the final two pairings who could make some noise on Sunday. John Senden (-13): The 2006 champion hasn’t made a bogey since his final hole on Thursday. Since then, he’s racked up nine birdies and an eagle, shooting consecutive 31s on the front nine. Another low-scoring front side on Sunday could put him right in the mix down the stretch. Jamie Lovemark (-12): No one needs a strong showing this week as much as Lovemark, and he knows it. Nothing less than a victory would allow the 24-year-old to keep his status on TOUR though a high finish could net him conditional status for the rest of 2012. Scott Piercy (-12): Piercy is riding a streak of 12 consecutive under-par rounds at TPC Deere Run and has already shown an ability to put together a stellar Sunday. At the Transitions Championship, he closed with a 9-under 62 to slide into a fifth-place tie. Robert Garrigus (-11): The big-hitting Garrigus has taken 28 or more putts in each of the first three rounds but still finds himself just outside the top 10. If he makes just a couple putts Sunday he could make a tremendous move. Brendon de Jonge (-10): He’s tied for third this week with 19 birdies but has offset many of them with seven bogeys and one double. If he keeps the card clean Sunday, de Jonge could be at 14 under, right in the mix, before the final groups reach the first tee.