49ers Pre/Post March 18, 2021 7:25 pm Pro Bowl center Alex Mack explains why he signed with Kyle Shanahan's 49ers 49ers new Pro Bowl offensive lineman Alex Mack explains why San Francisco was the perfect destination for him after he signed a three-year contract with the Niners. 49ers videos 2:01 Aldon Smith reflects on NFL career, lessons learned 0:58 49ers Talk: 49ers sign Terrell Owen's son Terique as undrafted free agent 1:25 49ers Talk: Is ‘writing on the wall' for Samuel's future in San Francisco? 1:30 Watch Brenden Rice's receiving highlights from USC 1:32 Watch Frank Gore Jr.'s rushing highlights from Southern Miss