Trent Baalke didn’t leave the new 49ers regime much. But he did find a cornerback in the fourth round of last year’s NFL draft that has a chance to be a building block-type player.

LSU alum Rashard Robinson is entering his second season as a clear favorite to start on a defense that badly needs revitalization after finishing last in many important categories in 2016.

Consider: Robinson as a rookie, per Pro Football Focus, allowed in coverage 22 of 44 receptions (50 percent, fourth-best among NFL corners), 310 yards, three touchdowns and made one interception – a solid 86.4 quarterback rating against.

But a bulk of the receptions allowed came in two games: Week 7 against Tampa Bay and Week 17 against Seattle. In those contests combined Robinson allowed 11 of 13 completions for 152 yards and all three of his touchdowns.

Quarterbacks targeting Robinson in every game but those two had a 35-percent completion rate and a passer rating of just 39.4. For a rookie, that’s promising. This year, his goal should be to avoid those bad weeks and become more consistent.

Really excited to see Rashard Robinson's progress in Year 2. Dude's coverage skills are insane. — Matt Miller (@nfldraftscout) May 16, 2017

The 49ers need Robinson to take the next step in his development and become a true shutdown corner if the defense is going to take a significant step toward improving. Last season it ranked 28th in net yards passing per attempt.

The good news: Robinson fits well in San Francisco’s new defense that emphasizes pressing receivers at the line of scrimmage.

Robinson (6-1, 177) needs to get stronger and be a more willing tackler against the run. But his 32 1/4-inch arms and 4.44 speed give him an intriguing blend of length and athleticism to hang with the league’s top wideouts.

He came into the league with physical tools teams covet early in the draft, but also a myriad of questions off the field, which included getting kicked off LSU’s team in 2015 and deciding not to transfer. He sat out the year before entering the draft.

The 49ers cornerbacks in 2017 form a mostly unproven group that’s losing two starters from last season. Tramaine Brock was released in April after an arrest for alleged domestic violence while Jimmie Ward is moving to free safety.

The other corners are Dontae Johnson, recent third-round pick Ahkello Witherspoon, Will Redmond (who sat his rookie season in 2016 recovering from an ACL tear), Keith Reaser, K’Waun Williams, Prince Charles Iworah, seventh-round pick Adrian Colbert and undrafted rookie Zach Franklin.

[h/t Jeff Deeney, Pro Football Focus]