Pitta caught 18 passes for 188 yards and two touchdowns in the first two games and has 30 receptions for 276 yards overall, emerging as one of quarterback Joe Flacco's most frequent targets.
Over the past four games, though, Pitta has generated only a dozen catches for 88 yards and no scores and was shut out against the Browns on Sept. 27.
Harbaugh acknowledged that teams may have shifted their schemes to try to slow down Pitta, but emphasized there's more nuance to what's happening on the field.
"It’s probably some of that," Harbaugh said. "To me, it’s a product of everything across the board. Typically, you say, ‘OK, this guy’s not involved. That guy’s not involved.’ It’s something you can take a look at, but when you start breaking it down and you start studying it, what you really find out is it’s more a product of us executing. It’s more a product of all the things, whether it’s protecting the quarterback or running the ball or getting more plays or getting first downs to create more plays.
"It’s guys getting open or making plays or making catches or making throws. That part of it, it all goes together. So, and, we’ve talked about this before, what you really want to do is, you define certain problem areas, and you try to go hard and correct them. But you also try to get better across the board. It’s never really one specific key that unlocks the puzzle. It’s a matter of forging ahead on all fronts and seeing if you can improve your play in each phase.”