IRVING — World No. 7 Louis Oosthuizen withdrew from the final round of the HP Byron Nelson Championship with neck stiffness, putting in jeopardy his start as the only top 10 player in the field in this week’s Crowne Plaza Invitational at Colonial.Oosthuizen, the 2010 British Open Champion, dealt with a similar injury before pulling out of the 2012 Honda Classic after the third round.He was tied for 32nd entering Sunday’s final round. Under PGA Tour rules, he receives earnings for 71st place, but his Nelson earnings will be unofficial because he withdrew during the event.World No. 12 Matt Kuchar would be the highest-ranked player in the Colonial field if Oosthuizen withdraws, although the South African had yet to do so officially as of Sunday night,If Oosthuizen considers playing this week, he could receive a medical waiver to skip Wednesday’s pro-am round but still compete in the tournament’s regular rounds.Cut-line magicWeb.com Tour graduate Morgan Hoffmann of Oklahoma State rallied with 66s on Saturday and Sunday to climb into a tie for fifth in the Nelson, his first top 10 of the season.Hoffmann struggled to start the season and fell out of the reshuffle position needed to earn an invitation to Colonial.The PGA Tour rookie was disappointed to learn he would miss Colonial after initially thinking the top 10 had earned him an automatic invite.“It doesn’t look like I’m getting in after all, but overall I felt great about the day,” he said. “I switched putters after the first day and really putted well this week with my old trusty.”Third time a charmZack Fischer’s 76 Sunday wasn’t much to write home about personally for the former UT Arlington golfer.It was, though, the first check cashed in a PGA Tour event by a former Maverick.Fischer said his putting abandoned him in the final round and that he struggled somewhat with the wind in carding a final 285 to tie for 68th.“Hit a lot of poor iron shots, and I was actually happy to shoot 76 as poorly as I hit it today,” Fischer said. “I had three balls in the water and hit some terrible drives, but I made it a lot harder than it actually was.”Fischer has qualified on Mondays for the last three open PGA Tour events and said with Colonial and Memorial coming up, he’ll take a few weeks off before deciding his summer plans.“I’m getting ready for sectionals for the U.S. Open,” Fischer said. “I’ve played 3 1/2 months straight without a break, and I probably ran out of gas a little bit today.”Fischer played with Ricky Barnes, who had one of Sunday’s low rounds with a 66.“He played from the ladies’ tee,” Fischer joked.Schwartzel in formCharl Schwartzel, the 2011 Masters champion, returned to form with a third-place finish in the Nelson.He ranked 20th in putting for the event, a testament to the form he showed before an abdominal injury in June.“I thought I hit the ball unbelievably, controlled it well in the wind, and the putter was as cold as it can be,” he said. “I hit one bad shot on the last hole and it was penalized with a downhill lie, so what can you do?”The South African will tee it up this week at Colonial.“I’m looking forward to it,” he said. “I like to add a couple of events to my schedule each year, and these two being so close just made sense.”Briefly• Officials confirmed tournament dates for the 2014 HP Byron Nelson will be May 15-18, the week after The Players Championship.• Mansfield’s Martin Flores (74) finished tied for 43rd and has made seven of eight cuts with one top 10 on the tour this year.• Masters runner-up Angel Cabrera shot 71 and finished tied for 12th.