Miami Dolphins enter difficult stretch with offensive line injuries. Where things stand

The Dolphins have flourished in the shallow end of the pool, feasting on five opponents with a combined 14-37-1 record.

They’re about to be thrown in the deep end, and likely — at least for a time — without Terron Armstead, their 6-5, 305-pound life jacket.

The Dolphins (8-3 and leading the AFC East) will now confront things they haven’t since September: an elite defense (in San Francisco on Sunday) and then two elite quarterbacks on the road against the Chargers (Justin Herbert) and Bills (Josh Allen).

And at least initially, they will likely be doing it without Armstead, the Pro Bowl anchor of their line. He will miss some time with a pectoral strain, with the expectation of a return at some point in December. NFL Network said it is a Grade 2 strain, which is a partial tear.

McDaniel said he’s confident Armstead will play again this season, but that the veteran left tackle is seeing a specialist to determine treatment options and a potential timetable. Miami has six regular-season games remaining.

Asked if Armstead might be ready to play in two or three weeks, McDaniel said: “Definitely wouldn’t put that past him. But we are gathering information, seeking all specialists and kind of letting the injury settle a hair, so the information can be a little more concrete and a little clearer. We’re evaluating some options with him in terms of how to treat it and stuff.

“But you know how I feel about Terron. He’s the consummate pro, so I’d be really foolish to go ahead and stamp an exact timeline because you just never know. It might be right around the corner.”

Offensive lineman Austin Jackson also is now sidelined with an ankle injury to the same ankle that sidelined him for eight weeks. He left late in Sunday’s 30-15 win against Houston.

McDaniel said the nature of Jackson’s injury was different than the one he sustained in Week 1, calling it a “weird freak thing that was pretty violent,” and adding that he will be “hanging out in the training room.”

Without Armstead, the Dolphins will need to come up with a way to block 49ers star edge player Nick Bosa (who has 10.5 sacks) and figure out how to score against a defense that has permitted just 281.7 yards per game (best in the league) and 15.7 points per game (also best in the league) and is eighth in sacks with 33.

“If Nick Bosa has a pulse, you’re concerned,” McDaniel said when asked about Miami playing him with or without its starting tackles. “He’s the best pass rusher in the NFL. You’re never going to stop him.”

The 49ers have won four in a row and haven’t allowed a point in the second half of any of those games.

The Dolphins pose a formidable challenge, ranking third in yards per game at 386.7 and sixth in points per game at 25.6. But an offensive line which had allowed just two sacks in 4 ½ games with Armstead unraveled without him.

There’s no appealing solution at left tackle, and McDaniel wasn’t going to reveal the short-term plan to replace Armstead. A look at the options:

▪ Brandon Shell: He’s far better as a right tackle, where he didn’t allow a sack for five consecutive starts before the Dolphins replaced him with Jackson to start the Houston game.

But the Dolphins inserted Shell at left tackle when Armstead left late in the first half on Sunday, after 37 snaps.

The results were regrettable. The Dolphins promptly permitted four sacks over a 10-play stretch. Pro Football Focus did not blame Shell primarily for any of the sacks — though he certainly had a role in at least one — but noted that he gave up five pressures in 23 pass blocking chances.

Shell, who has played nearly all of his career at right tackle, also was asked to play left tackle against the Jets, after Armstead left early in the game. He permitted four quarterback hits and seven pressures in 35 pass rush chances in that game.

So, per PFF, that’s 12 pressures allowed in 55 pass rush chances for Shell at left tackle this season. So putting Shell against Bosa on Sunday seems less than ideal.

▪ Greg Little: He played left tackle — with Shell moving to right tackle — after Jackson joined Armstead on the sidelines late Sunday.

Little’s previous start at left tackle this season was a disaster. With Armstead sidelined, Little permitted three sacks and 11 pressures against Minnesota. At least Shell played well at right tackle in that game.

▪ Jackson: If he’s healthy enough to play Sunday — and that’s very much in doubt — the Dolphins have the option of moving Jackson back to left tackle. But he spent the offseason and training camp at right tackle, and the Dolphins prefer to keep him at that spot.

Jackson relinquished four sacks and 38 pressures at left tackle as a rookie in 2020, then yielded 20 pressures in three games to start last season before being moved to guard.

Needing tackle depth, the Dolphins added veteran Kendall Lamm to their practice squad Monday. He has played in 86 games plus seven playoff games with 28 starts; he played last season as a backup in Tennessee.

Lamm, 30, made 13 starts for Houston in 2018, but has just four starts for the Browns and Titans in three years since then. “He’s done a good job” in his career, McDaniel said. He has played more than 1,000 snaps at right tackle and 351 at left tackle.

If the Dolphins cannot block Bosa and the 49ers, that could significantly impact their strategy. Tua Tagovailoa likely will need to get the ball out quickly.

Tagovailoa leads the league in passer rating at 115.7, and much of his success has come on intermediate or deeper routes that would be difficult or impossible to complete if he has no time to throw.

Tagovailoa’s 63.9 percent accuracy this season (23 for 36) on passes thrown at least 20 yards leads the league, but those plays need effective blocking to develop.

Defensively, the competition also stiffens in December. In their next four games, the Dolphins are set to face quarterbacks who rank fifth in the league in passer rating (Jimmy Garoppolo at 103), 14th (Justin Herbert at 92.7), ninth (Josh Allen at 95.2) and if he’s healthy, 13th (Aaron Rodgers at 92.9). Only the Green Bay game is at Hard Rock Stadium.

The quarterbacks the Dolphins have beaten during this five-game winning streak rank 35th (Kenny Pickett), 12th (Jared Goff), 26th (Justin Fields), 20th (Jacoby Brissett) and 36th (Kyle Allen).

The Dolphins are 27th in passer rating against; only five teams are permitting a higher rating than Miami’s 96.3.