The biggest changes won’t be at coaching for the 49ers this year. Rather, the eye-popping player turnover is the main news. In addition to six major free agency losses, a fourth player has now suddenly retired. Right tackle Anthony Davis is only 25 years old but joined teammates Chris Borland (24), Patrick Willis (30) and Justin Smith (35) in hanging up the cleats. Clearly Davis, Borland and Willis had promising and lucrative NFL futures yet these three on the same team chose to walk away. I can’t think of three similar circumstances across the other 31 NFL teams combined. Barry Sanders retirement from the Lions in his prime is still talked about today. However the third all-time leading rusher played 10 years. Davis is on his first contract, Borland only played one year and Willis retired younger than when Sanders did. To make matters worse, 2014 starters Frank Gore, Michael Crabtree, Mike Iupati, Ray McDonald, Chris Culliver and Perrish Cox signed with other teams as free agents (and Andy Lee was just traded). Marcus Lattimore also retired; however, his was exit was due to inability to overcome a multi-ligament knee injury and he never played in the NFL. Glenn Coffee also retired in 2010 after a successful rookie season. Davis steps away saying he would “take a year or so away…to allow my Brain and Body a chance to heal”. This sounds similar but less permanent than Borland’s retirement. All that remains of the dominant 49ers offensive line that had the same five starters over the years of their recent success is left tackle Joe Staley and right guard Alex Boone. I wrote last week how the 49ers lead the league and more than doubled the second place team with nine players coming off of ACL surgery. These retirements seem to be even more unprecedented than the ACL recoveries. This offseason, the 49ers will have lost a combined 20 Pro Bowl seasons. The question is why? Worry about health and safety issues? Is it due to Jim Harbaugh’s departure, or in spite of it? Business moves? Loss of faith in the team or front office? Purely coincidence? Or combination of all of the above? Or is there really something in the San Francisco water? MMMD 1: Carson Palmer ahead of other quarterbacks The Cardinals signal caller had a second-time ACL tear in November of 2014 and is slated to participate in 11-on-11 drills this week. At this rate, he projects to be ready for the 2015 season opener, especially as a veteran calling plays in the same system. Sam Bradford had a three-month head start on Palmer with his August ACL re-tear but has been seen with a limp and only recently partially participated in 7-on-7 drills with his new team. The Raiders’ Derek Carr has been limited to run game installation. He has reported finger numbness and is waiting to throw. The 35 year old Palmer is on track to show up the young guns at this point. MMMD 2: Dolphins first-round pick needs surgery DeVante Parker excited Miami fans in OTAs, but the announcement of foot surgery now creates angst. The former Louisville wide receiver had a screw inserted for a fifth metatarsal stress fracture just prior to his senior season and returned to play well the later half of year. Now a new screw has been inserted in his Jones fracture. Re-injury or incomplete healing does happen with this injury as it did with the Falcons’ Julio Jones in 2013. Likely the Dolphins decided to perform the procedure now to avoid a lingering problem that might impact more of the regular season if they waited. The surgery was immediately termed “successful”. Calling surgery a “success” right after the procedure is like saying a team’s draft is a “success” before any games are played. The key here is getting the bone to heal over time. If the bone unites fully, Parker should not have a problem long term. The question now is which will come first: true success and healing or the start of the 2015 season. MMMD3: Patella tendon ruptures can end careers Greg Childs had a promising NFL career as a forth-round draft choice out of Arkansas despite one torn patella tendon. He then tore both patella tendons at the same time prior to his first campaign with the Vikings in 2012. Despite many years of hard work, it appears his football playing days are finally over. During CFL training camp, unfortunately he tore his Achilles tendon. Childs has made a valiant effort to return but just couldn’t overcome the odds of bilateral tears. The Giants’ Victor Cruz only has a single rupture so the hope is he can return to full speed this fall. Kyrie Irving’s patella stress fracture is an entirely different injury. He should have a quick 3-4 month recovery after surgery, as bone-to-bone healing is quicker than tendon-to-tendon. Blake Griffin had a similar patella injury in 2010 and has returned to full form. MMMD 4: No news is good news for Junior Galette The Saints outside linebacker reportedly suffered a pectoral injury. It is unclear where (pec muscle or tendon) or when (at team facility or on his own) the damage occurred. The key is if the muscle is involved or a partial tendon, conservative care is possible. If the pec tendon is completely torn, surgery and months of missed time is inevitable like for the Giants’ Will Beatty. I take a report from NFL Network’s Ian Rapoport on a split opinion for surgery as potentially good news. If the pec tendon were completely torn, that finding and the decision for surgery would be obvious. The ”delay” should give Saints fans hope that their double-digit sack producer still has a chance to avoid surgery and play this year. MMMD 5: Kickball injury Any injury suffered during a team building activity is unfortunate. When the activity is kicking a ball and the kicker is injured, it becomes cruelly ironic. Dolphins’ Caleb Sturgis injured the quadriceps (thigh) on his plant leg. Although he will miss the rest of OTAs, the hope is he will return for the start of training camp. My guess is the next team building activity will be at a movie or the arcade. MMMD 6: Rams draft pick wasted with failed physical In the NFL, it is not unheard of to fail a physical, but it is unusual for a draft pick to not pass and be waived due to on going medical concern. A main purpose of the Combines is to examine players, but Rams sixth-round draft pick Bud Sasser was not invited to Indianapolis and was not brought in to St Louis for a pre-draft visit. The ex-Missouri four-year wide receiver was discovered after the draft to have a heart condition that is presumed to be a form of cardiomyopathy. His agent claims that a second opinion at the Mayo Clinic has cleared him to play. The Rams may have failed Sasser, but they seem to have treated him well. He was signed to a contract and still will be paid his $113,737 signing bonus prior to being released with non-football injury designation. Apparently the other 31 teams don’t seem excited about clearing Sasser medically either as he cleared waivers. [caption id="" align="alignright" width="474"] Hardwick's before and after pictures.[/caption] MMMD 7: Extreme weight loss Much has been made of former Chargers Pro Bowl center Nick Hardwick’s 85-pound weight loss upon retirement. On ESPN’s Pardon the Interruption, host Tony Kornheiser commented, “it is eyebrow-raising” and implicated performance-enhancing drug use. Eat dinner with Hardwick and one would easily see how he has lost the weight. I have dined with him on several occasions (charity events, out with the boys and family dinners) and he eats very healthily with small portions and an essentially paleo diet. If I ate that way, I would leave meals hungry. Typically, ex-football players don’t maintain their same playing weight. The ones that struggled to keep pounds off predictably gain. Those that struggle to keep up weight end up dropping pounds. I know several teammates of Hardwick’s who have also lost considerable weight because they want to be healthy now, but previously piled on weight to stay in the NFL. Hardwick and others like him should be applauded for their weight loss, not looked at suspiciously. Follow David on Twitter: @profootballdoc Dr. David Chao is a former NFL head team physician with 17 years of sideline, locker and training room experience. He currently has a successful orthopedic/sports medicine practice in San Diego.