Ashton Jeanty had a poor preseason debut for the Las Vegas Raiders last week against the Seattle Seahawks. He had minus one rushing yard for three carries while the game finished in a tie with a 23-23 scoreline. However, the rookie made significant improvement in his game against the 49ers on Saturday.The Raiders suffered a 22-19 defeat at the hands of Kyle Shanahan's team. After the showdown, 4-time Pro Bowl DE Maxx Crosby spoke about Jeanty.Crosby expressed confidence in the ex-Boise State star's abilities and talent while praising his big play against the 49ers."It was crazy," Crosby said. "You know, Ashton is a top-10 pick for a reason. So it was good to see him get a little bit more of a breathing room in the backfield. It was awesome. He definitely runs the ball with emphasis for sure. It was a helluva run and you just see him everyday show up to get better. So yeah, I love what that kid's done."... The way he runs the ball, he's so compact and strong ... that's why he had so much success at Boise State. You know, we're really excited about him and we're looking forward to him being a big part of what we're doing."Ashton Jeanty gave fans a scare in the first quarter. He was sidelined momentarily after injury concerns to his shoulder. However, after having his assessed at the medical tent, the rookie RB returned to the field, leading to fans breathing a sigh of relief. He ended the night with 33 rushing yards for seven carries and one rushing TD.Geno Smith is excited about Ashton Jeanty's debut campaign with the RaidersThe Raiders acquired veteran quarterback Geno Smith in a trade with the Seahawks in the offseason. He is gearing up to take over as the starting quarterback this upcoming season.After their 22-19 loss to the 49ers on Saturday, Geno Smith expressed his excitement about Ashton Jeanty."It fires me up just seeing the way (Jeanty) runs," Smith said as per ESPN. "He's running through people, and he's not shying away from contact."The Raiders take on the Arizona Cardinals in their final preseason game next week. They kick off Week 1 with a showdown against the Patriots on September 7 at Gillette Stadium.