SANTA CLARA — The 49ers won’t open their regular season for about six months (Sept. 9 or 10) but here is how their defensive starting lineup looks after an early jump on free agency:
Defensive tackles: DeForest Buckner, Solomon Thomas
Analysis: The 49ers’ top picks in the past two drafts are best utilized on the interior to push the pocket, and Buckner could break through as an All-Pro this season. Thomas, like most of the 49ers lineman, can play on the interior and edge, so consider the defensive front’s depth chart quite loose. Backup: Sheldon Day, Ronald Blair.
Nose tackle: Earl Mitchell.
Analysis: Mitchell, 30, is the defense’s oldest player, and he proved solid against the run in his 2017 debut with the 49ers. Backup: D.J. Jones.
‘Leo’ pass rusher: Arik Armstead.
Analysis: An overdue, big season out of the 2015 first-round pick who has six career sacks, with his 2019 fifth-year option still up in the air. Cassius Marsh (re-signed) and Jeremiah Attaochu (Chargers) are candidates to start, too. Backups: Marsh, Attaochu.
Strong-side linebacker: Eli Harold.
Analysis: Harold could get a crack at more pass-rushing duties but has been best against the run. Backups: Dekoda Watson, Pita Taumoepenu, Jimmie Gilbert, Boseko Lokombo
Weak-side linebacker: Malcolm Smith.
Analysis: Smith will be making his 49ers debut after sitting out 2017 with a torn pectoral in camp. Backups: Mark Nzeocha, Donavin Newsom
Middle linebacker: Reuben Foster.
Analysis: Offseason arrests cast a cloud over Foster’s availability and the 49ers must brace for potential league discipline (even if he’s not charged). Otherwise, a Foster-Smith tandem looks enticing. Backups: Brock Coyle, Elijah Lee.
Left cornerback: Richard Sherman.
Analysis: We won’t know for a few months how Sherman’s Achilles tendons respond on the field. Maybe the 49ers bide that time by developing a high draft pick. Backup: Greg Mabin, Tyvis Powell
Right cornerback: Ahkello Witherspoon.
Analysis: The 49ers are counting on Witherspoon to build off his rookie season’s gradual improvement. More depth and competition is needed in this unit. Analysis: Backups: Channing Stribling, Trovon Reed.
Nickel back: K’Waun Williams.
Analysis: His one-handed interception against the Jaguars was inspiring. It’s to-be-determined who will challenge him for the nickel role.
Free safety: Jimmie Ward.
Analysis: Ward’s $8.5 million salary is staggering for someone with more season-ending injuries (three) than interceptions (two). Colbert is a physical, entertaining, high-wire act, so maybe Ward slides back to cornerback. Backups: Adrian Colbert, Chanceller James
Strong safety: Jaquiski Tartt.
Analysis: Tartt, a versatile and hard-hitting safety, is in the final year of his rookie deal but should land an extension. Backups: Dexter McCoil, Don Jones
