SAN DIEGO -- Upgrading the cornerback position for the San Diego Chargers remains the focus in the latest mock drafts published by ESPN draft analysts Mel Kiper Jr. and Todd McShay.

Even though San Diego’s pass defense was much better during the stretch run of the team’s surprise entry into the postseason, the Chargers had just 11 interceptions during the regular season, tied for No. 26 in the league, and allowed an average of 258.7 passing yards a contest (No. 29 in the NFL).

In this ESPN Insider piece, Kiper Jr. selects Florida cornerback Marcus Roberson for the Chargers at No. 25. Roberson makes some sense, particularly because at 6-0 and 195 pounds, he gives San Diego some much-needed size at the position. In his first mock draft, Kiper Jr. had the Chargers taking Ohio State cornerback Bradley Roby. Here is what Kiper Jr. had to say about Roberson.

Kiper Jr.: “The Chargers did a pretty good job of scheming their way around some holes at corner during the late-season run, but there's no question they could use another good cornerback (or two), particularly because I think that defensive line and pass rush could take another step forward next season. Roberson can get a little lackadaisical, but it can also look easy for him out there because he has good instincts and a sense of where routes are going. He has long arms and can get his hands on the ball. He simply needs to be more physical against the run and grab a little less in coverage.”

In this ESPN Insider piece, McShay has the Chargers selecting a different cornerback from the University of Florida, Loucheiz Purifoy, at No. 25. In his first mock draft, McShay gave the Chargers Oklahoma State cornerback Justin Gilbert. Purifoy makes sense because of his athleticism and playmaking ability at 6-foot and 190 pounds. Purifoy also has the ability to return kicks, another high-priority need for San Diego. Here’s what McShay had to say about Purifoy.

McShay: “The Chargers need to upgrade at cornerback and in the return game, and Purifoy could help in both areas. He is raw with his technique but has the potential to develop into a playmaker at corner because of his very good ball skills, and because he's one of the most naturally talented defensive backs in this draft. If the Chargers pass on Purifoy, they could go with a smaller but equally skilled and more polished cover corner in TCU's Jason Verrett. If they take a CB here, they could target a pass-rusher like Auburn's Dee Ford in Round 2 and a guard like Baylor's Cyril Richardson in Round 3.”