Right side of 49ers offensive line showing its warts

Colin Kaepernick was sacked five times by the Steelers on Sunday. AP Photo/Don Wright

The San Francisco 49ers' rebuilt offensive line, with only one starter remaining at the same position he played at in the 2014 opener (paging left tackle Joe Staley), was a concern entering this season.

But in the Niners' dominant season-opening 20-3 victory over the Minnesota Vikings, the O-line was a strength in springing Carlos Hyde for 168 yards rushing.

Less than a week later, though, those preseason concerns and, well, warts came to the forefront in a 43-18 blowout loss at the Pittsburgh Steelers.

"Up and down," said Niners coach Jim Tomsula on Monday, when asked to describe the play of his O-line.

"There was obviously a couple of plays there that we wished we could have protected a touch longer. But, there were also some really good things. That group there's steadily moving."

Pro Football Focus, though, saw things a little differently. Especially for the right side of the line against the Steelers. Remember, Colin Kaepernick was sacked five times.

Consider: center Marcus Martin was given a grade of minus-2.1.

Right guard Jordan Devey, acquired in a trade with the New England Patriots on Aug. 18, had a grade of minus-3.4, with minus-3.8 on pass blocking by giving up a sack and six hurries.

And veteran right tackle Erik Pears was slapped with a grade of minus-6.4.

The season may only be two games old for the Niners, but after Sunday's games, Pears ranked 64th out of 70 tackles in the league with grade of minus-8.7, while Devey (minus-5.8) was 65th of 71 guards and Martin (minus-4.5) was 27th of 32 centers.

Also, as a whole, the 49ers offensive line has a Pass Blocking Efficiency rating of 66.3, last in the NFL, per PFF.

Up and down? It would appear there's only one way for the right side of the O-line to go.