There are several aspects to pay close attention to when the San Francisco 49ers begin training camp in a couple of weeks.One of the most important ones is the battle for these three positions. Its results can help or hurt the 49ers' success in 2026. Let's dive into those position battles.Left GuardOct 19, 2025; Santa Clara, California, USA; San Francisco 49ers guard Connor Colby (75) before the game against the Atlanta Falcons at Levi's Stadium. Mandatory Credit: Darren Yamashita-Imagn Images | IMAGN IMAGES via Reuters ConnectWith Spencer Burford and Ben Bartch (ridiculous starter) gone, the 49ers will hold a competition to see who will be their best starting left guard. Second-year player Connor Colby is currently the lead favorite.He’ll have rookie Carver Willis and veteran Robert Jones to push him. I wouldn’t give Willis much of a chance. He’s moving from tackle to guard, which will probably require him a full season to cleanly make the transition.Besides, it’s not like the 49ers have come close to hyping him up or citing any traits they’re in love with. That leaves Colby with Jones to fend off. It won’t be easy, as Kyle Shanahan favors the veterans.Colby can’t afford to play errantly numerous times. If he messes up here and there, so be it. He just can’t look unreliable, especially if he’s failing to nail assignments and make the right reads with his blocks. He’ll lose his job to Jones if that’s the case.Cornerback Dec 14, 2025; Santa Clara, California, USA; San Francisco 49ers cornerback Renardo Green (0) tackles Tennessee Titans wide receiver Chimere Dike (17) during the fourth quarter at Levi's Stadium. Mandatory Credit: Cary Edmondson-Imagn Images | IMAGN IMAGES via Reuters ConnectIt became steadily clear that the 49ers aren’t going to pencil Renardo Green as the starter opposite of Deommodore Lenoir as they did last year. Their additions to the position prove that.Jack Jones and rookie Ephysians Prysock will be chomping at the bit to supplant Green. It’s all part of the 49ers’ plan to light a fire under Green to get the most out of him. He has the upper hand since he’s the better talent than Jones, and Prysock is a rookie. Green won’t have much to worry about with Jones. Prysock, however, is a wild card.Yes, he’s a rookie, so he should lose to Green. But he has extraordinary physical skills that can stand out in camp and the preseason. All he needs is to put it all together, and he’ll end up giving the 49ers a difficult choice. Safety Nov 16, 2025; Glendale, Arizona, USA; San Francisco 49ers safety Malik Mustapha (6) reacts in the second half against the Arizona Cardinals at State Farm Stadium. Mandatory Credit: Joe Camporeale-Imagn Images | IMAGN IMAGES via Reuters ConnectIt’s safe to say that Malik Mustapha is the locked-in starter for the 49ers this year. Ji’Ayir Brown might already be the other starter they have in mind as well, but I’d imagine Raheem Morris wants a competition.It’ll come down to who’s better between Brown and Marques Sigle. You can even throw in Ashtyn Davis into the competition. The 49ers’ safeties are so underwhelming that they need to consider everyone at the position.But the ones that are likely to start next to Mustapha are Brown and Sigle. For the 49ers’ sake, it needs to be Sigle. If he can sure up his pass coverage when the ball is in the air, he’ll be adequate.He’s already proven he can defend the run well, but if Mustapha is going to spend much of his time in the box, they need Sigle to be sound in coverage. He has the talent for it. Perhaps Morris can get it out of him. Follow Jose on X (Twitter) @JS3sanchezz to interact with him on the 49ers and more.Add us as a preferred source on GoogleFollow