The absence of Pro Bowl tight end Vernon Davis and backup Vance McDonald Sunday was the incentive for the San Francisco 49ers to change their offense against the Arizona Cardinals from a power-running scheme to a pass-happy attack that featured four- and five-wideout sets.

There was a lot of success early, though little to none late in the 23-14 loss.

This coming week, though, with the high-powered Philadelphia Eagles coming to town, Davis’ injured left ankle and knee healing sufficiently enough for his return could also mean a return to normalcy for the 49ers' offense.

“Optimistic,” Harbaugh said in his weekly news conference Monday when asked for an update on Davis. “Very hopeful that he’ll be able to play Sunday.”

McDonald, who is nursing a right knee injury, is primarily the team’s blocking tight end.

So why did the Niners flip the offensive script?

“Part of it, because we thought it would work,” Harbaugh said. “And there was personnel to consider … both of those things.”

Also, defensive lineman Ray McDonald suffered a dislocated finger in the game, coming off the field with 3:57 to play, per Pro Football Focus.