SANTA CLARA, Calif. — San Francisco 49ers coach Jim Harbaugh instructed his players to relax and enjoy the time off during the team’s bye this week. But the fact is: There is reason for concern.

After all, if the 49ers spent their vacation lying on their backs, they did so looking up at six teams in the NFC standings. That would put them on the outside looking in if the postseason started today.

Alas, a 4-3 record doesn’t sound so bad when you consider the 49ers, according to the calculations of nationally respected analyst Jeff Sagarin, played the NFL’s second-hardest schedule (behind Kansas City) in the first seven weeks of the season.

Ahead lies seven consecutive non-winning teams before a tough two-week conclusion.

Maybe that’s why Harbaugh’s final instructions to his guys Monday morning were: “Enjoy their families, enjoy their children if they have them, play with their kids.”

Be forewarned, however: The upcoming schedule isn’t as cushy as it sounds. Included in the next seven games are two matchups with Seattle (3-3) and long trips to New Orleans (3-4) and New York (Giants, 3-4).

The regular season ends at home against San Diego (5-2) and Arizona (5-1). If it takes 10-6 to make the playoffs in the NFC, the 49ers would need to win at least two games in that Seahawks-Saints-Giants sequence in order to have the luxury of splitting the two season-enders and still get in.

Rounding out the remaining schedule is St. Louis (2-4), Washington (2-5) and Oakland (0-6).

Statistically speaking, the 49ers wouldn’t seem like a team that hasn’t played playoff-caliber football this season. Entering their bye, they rank ninth in total offense and sixth in total defense.

Breaking those numbers down, one area of concern can be identified on each side of the ball.

The 49ers are barely average (14th of 32) in passing offense. They’ve allowed the fifth-most sacks (19) and have just the 20th-best completion percentage (62.9).

Defensively, they are average (16th of 32) against the pass. They’ve allowed the fifth-most touchdown passes (13) and have just the 21st-most sacks (12).

Progress report on 49ers who missed all or part of Sunday’s 42-17 debacle at Denver:

–Expected to return for next game (Nov. 2 vs. Rams) — guard Mike Iupati (concussion), inside linebacker Patrick Willis (toe), cornerback Chris Culliver (hamstring), cornerback Chris Cook (hamstring) and safety Jimmie Ward (quad).

–Scheduled to practice for first time this season next week — Running back Marcus Lattimore (knee).

–Slated to return Nov. 16 (at Giants) — Outside linebacker Aldon Smith (suspension).

–Hopeful of returning on or around Dec. 1 — Nose tackle Glenn Dorsey (biceps) and inside linebacker NaVorro Bowman (knee).

The 49ers lost starting center Daniel Kilgore to season-ending leg surgery in the Denver game. Rookie Marcus Martin is expected to start in his place.