While the 2025 NFL season is almost here, it seems like the teams are still not done making some big moves. The Washington Commanders are reportedly trading their star running back, Brian Robinson Jr., to the San Francisco 49ers.Many are predicting that this trade will have some major implications for the Niners' RB1 Christian McCaffrey's fantasy football stock. Reacting to the trade, some fantasy football managers took to social media.While some believe Robinson's arrival will devalue McCaffrey, others think that it would offer the Niners some flexibility."CMC STOCKED JUST DROPPED," a Fantasy Football Manager wrote."WOW! So many fantasy implications for both sides with this one," this player tweeted.Check out some more reactions below:"Commanders really not getting enough attention for brazenly undercutting the abilities of their young QB. Trading his best RB and refusing to pay his #1 WR. Front office/coaching staff flexing some serious egos thinking it doesn’t matter," tweeted an account."Well this certainly presents quite the lovely “how do you do” to my current FF draft strategy," stated this Fantasy Football Manager."dang changes the strategy if I want to go for JCM now as a sleeper. Just never trusted CMC and had him #1 last season," wrote a player.NFL veteran believes 49ers RB Christian McCarthy made some changes to his workout after suffering an injury last seasonChristian McCarthy has been a solid asset for the Niners over the years. However, last year he suffered a season-ending injury during a game with the Buffalo Bills in December. However, three-time Super Bowl winner Mark Schlereth shared his thoughts on the RB's recovery journey.While speaking on "The Craig Carton Show" last month, the NFL veteran said:"I've know Christian since he was born, so one of the things about Christian is that dude trains like no other," Schlereth said. "And so I think he's readjusting the kind of the amound of work he's doing. Because sometimes, I think he puts himself out so maximum effort in the offseason that he wears himself down a little bit. So we'll see exactly how that works."It will be interesting to see what the future holds for Christian McCarthy and the 49ers now that Brian Robinson Jr. has joined the roster.