There's a red flag for Robert Griffin III and the Browns one week before the season starts

It's difficult to come away with any substantial conclusions from NFL preseason.

However, if you've been following highlights of the NFL's exhibition games in recent weeks, you may have noticed that Robert Griffin III, fresh off a year-long vacation, has been showing signs of a comeback in Cleveland.

After sitting the entire 2015 season with the Washington Redskins, Griffin signed with the Browns this offseason. Though expectations are low for the team overall, the NFL world is curious how Griffin will operate with the reins once again in his hands.

And, so far, in preseason, the glimpses have been encouraging. He's connected with quarterback-turned-receiver Terrelle Pryor on some spectacular, deep routes:

And with tight end Gary Barnidge:

Unfortunately, ESPN's Pat McManamon is here with the dispiriting asterisk. Outside of a few highlight-reel plays - almost exclusively on deep, sideline routes - Griffin has been awful.

As McManamon notes, excluding five long completions, Griffin is 13-25 for 67 yards, an average of just three yards per attempt, with no touchdowns and one interception. Not great.

Additionally, in the five total quarters Griffin has played in preseason, the Browns are averaging five plays and 29 yards with him under center. Such meager offense has led to the Browns being outscored 71-37 in three preseason games.

Obviously, not all of this can be blamed on Griffin. He doesn't play defense, nor does he control his teammates' routes, hands, or success while running the ball. But outside of a few big throws and some crafty rushes (he appears to have greatly improved his slides on scrambles), Griffin doesn't look like he's developed the pocket-passing skills that were demanded of him in Washington.

Both Griffin and new Browns coach Hue Jackson know this. Griffin acknowledged his need to improve, according to Cleveland.com's Mary Kay Cabot.

"It starts with me. I just have to make sure that when the intermediate throws are there, I make them," Griffin said. "When the long ball throws are there I make them, and when the quick game throws are there, I make them. So it all starts with me and I'll make sure that gets cleaned up."

Jackson added, "We're going to have to run the ball better than we have and we're going to have to throw the ball better than we have. At the same time, I did see some flashes of some things that we can build from."

It's tough to take much away from preseason. Again, Griffin hasn't played a real football game since 2014, he's in a new offense and working with new teammates. Perhaps these issues will iron themselves out in a few weeks.

But if the Browns are going to continue to average three yards per throw, then it's going to be a long year in Cleveland.