49ers rookie Guerendo flashes speed with long preseason kick return

After sustaining a right hamstring injury toward the end of the 49ers' first training camp practice, running back Isaac Guerendo was not afforded many opportunities to showcase his 4.33-second speed this summer. He made up for it Friday night in the 49ers' preseason finale against the Las Vegas Raiders at Allegiant Stadium. Guerendo supplied one of the night's highlights when he blasted through an opening and broke a couple of tackles on his way to a 93-yard kickoff return in the second quarter. His return started at the left sideline and he angled his way across the field before he was taken down at the 4-yard line near the right sideline. "After changing direction and all of that stuff, it was probably about 140 yards," Guerendo said following the 24-24 tie. "It's the first time I've been able to open up a little, so it was exciting. When I got to that 15, I was like, 'My legs are getting a little bit heavy.' I just got to finish that one next time." Guerendo appears to be a good fit for the NFL's new kickoff rule with his combination of speed and power. He was the fastest running back at the NFL Scouting Combine. He is listed at 6-foot, 221 pounds. "It was my first time being...