“Running back Josh Jacobs, one of the team’s three first-round picks in April, is the only Raiders draft pick still unsigned and league sources say the negotiations have not been going well. There is a growing sentiment that Jacobs will not be at camp when rookies report on July 23. (The official start of camp — when the veterans report — is three days later.)”Rookie holdouts are rare in the NFL these days after the installment of a rookie wage scale, since contract values and signing bonuses are predetermined. But there is still wiggle room regarding the payment schedule of the signing bonus and whether salary guarantees will have offsets. The bonus issue is apparently the hangup between Jacobs and the Raiders.”Coach Jon Gruden was excited about the explosive rusher, who ran for 640 yards and 11 touchdowns on 120 carries last season. He also proved to be a dual threat, finishing his third and final year with the Crimson Tide catching 20 passes for 247 yards and three scores. “He’s physical, he’s dynamic,” Gruden said after the draft. “He’s a great story, indeed. Where this kid has come from. There is something inside of him that I didn’t go through as a young man, and I think he’s going to be a centerpiece at some point. I’m not going to put any pressure on him, he’s got a lot to learn.”But we do have a good offensive line, we’ve got an experienced quarterback in our system now, we’ve got a couple of receivers that if you want to double them, perhaps this running back can do some damage. So we’re excited at this addition to our team.” The Raiders could already be without one of their top rookies.After Oakland picked up a number of new additions in this year’s draft, one of its first-round picks could sit out of training camp after negotiations haven’t progressed, according to a report from The Athletic, which cited unidentified league sources. Josh Jacobs was selected as the 24th overall pick in of the draft, but the running back out of Alabama doesn’t seem happy with the team’s bonus structure. He is the team’s only draft pick that remains unsigned — defensive end Clelin Ferrell and safety Johnathan Abram both signed on June 18.But it doesn’t seem Jacobs is too thrilled about discussing a potential contract. Yahoo Sports captured a tweet, that has since been deleted, with Jacobs saying, “Blocking everyone the @ me abt a contract.”While Jacobs may not want to have these talks with nagging fans, the Raiders will hope he’s more forthcoming when they try to come to an agreement before training camp starts at the end of the month.But that doesn’t seem to be going well, The Athletic report noted.