The free-agency departures of three-time Pro Bowl center Alex Mack and right tackle Mitchell Schwartz seem to be haunting the Browns because their offensive line is trying to find its way with the Sept. 11 regular-season opener at the Philadelphia Eagles on the horizon.

Starting quarterback Robert Griffin III was sacked five times in two quarters Friday during a 30-13 loss to the Tampa Bay Buccaneers in the third preseason game for both teams.

The new starters on the offensive line, center Cameron Erving and right tackle Austin Pasztor, have struggled throughout the preseason. Each one surrendered a sack against the Bucs.

At this point, the Browns are supporting both players, sticking with them as the starters and hoping for the best.

Nine-time Pro Bowl left tackle Joe Thomas, left guard Joel Bitonio and right guard John Greco are established starters, but question marks at the other two spots are as big as they were March 9, the day Mack signed a five-year, $45 million contract with the Atlanta Falcons and Schwartz signed a five-year, $33 million deal with the Kansas City Chiefs.

“When you get guys that are coming in like Cam and Austin that weren’t starting there last year but are coming in as starters this year, the whole O-line rallies around each other,” Bitonio said Sunday during a conference call.

“Those are great players that we had last year that we lost,” Bitonio said of Mack and Schwartz. “But these guys have done a good job stepping up, and we are seeing improvement each week. I think as an O-line, we are really starting to come together. Obviously, there are some plays that we want to take back last week, but I think going into Philly, we are going to have a good group that is ready to take on some good defenses.”

The pass protection, though, must be better for Griffin to receive a realistic chance to revive his career, let alone stay healthy.

“We kind of got behind the chains a little too much, so that put us in passing situations, which puts us at a disadvantage,” Bitonio said. “There were some things that happened on the line where we just got beat, and then there were some things that they did well that put us in disadvantage situations where they brought one more guy than we can block or they had good coverage where we held onto the ball a little bit longer than we wanted to.

“We definitely got our quarterback hit more than we wanted to and it is something we are definitely going to strive to fix. It is never good when your quarterback gets sacked, regardless of if he ran out of bounds behind the line of scrimmage or he got hit.”

There is an important factor to consider about Griffin being sacked five times. Thomas, coming off a back injury, played just the first three series because the team is easing him back into action. Backup Dan France replaced Thomas early in the second quarter and played a role in allowing two of the sacks.

“Being a little selfish, I want to be out there with Joe as much as possible, but it is good to get some other guys out there and really try and build their confidence and help them out,” Bitonio said. “There is definitely a little bit of a drop off, but I think Dan and [rookie Spencer Drango] have been coming in and really trying to work and trying to improve.”

Although the offensive line had glaring issues in pass protection against the Bucs, it improved its run blocking. Isaiah Crowell rushed eight times for 39 yards (4.9 average, long of 13), and fellow running back Duke Johnson had three carries for 22 yards (7.3 average, long of 12).

“We are chasing perfection at every block we make,” Bitonio said. “There are definitely things to work on, but we saw life in the run game and saw things that if we stay on schedule, this could be a successful run game for us.”

And the offensive line could be successful as a whole if Erving and Pasztor get their acts together. They’re under the microscope, especially Erving because he was a first-round draft pick (No. 19 overall) last year.

“The one thing with Cam is every week you are going to get his best effort. He is definitely not afraid to play hard and play with energy and kind of bring that mentality to the team,” Bitonio said. “But I think technically he is still improving. He is still technically learning how to play center in the NFL.

“But the effort is there. The decision making is even better. Every game, you can see an improvement. You can see things where you’re like, ‘Man, that’s a really impressive play he made.’ There are obviously things that he is still working on. Luckily, it is still the preseason, and we are still a couple weeks before our first game.”

Nate Ulrich can be reached at nulrich@thebeaconjournal.com. Read the Browns blog at www.ohio.com/browns. Follow him on Twitter at www.twitter.com/NateUlrichABJ and on Facebook www.facebook.com/abj.sports.