In the four-week NFL preseason, the third game is considered the most important. Starters play little — if at all — in the final game because of injury concerns. Coaches expect to see progress in the key test before the regular season.

The Washington Redskins showed some progress Saturday afternoon in a 30-17 victory over the Indianapolis Colts at FedEx Field.

For Redskins fans, the main story line was the first meeting of rookie quarterbacks Andrew Luck and Robert Griffin III — the Nos. 1 and 2 selections in the 2012 draft — during a game in which the teams’ starters played into the third quarter. Fans are eager to watch their careers unfold while awaiting the results: Did the Colts get the better player in Luck or will Griffin become a bigger star for the Redskins? The matchup also intrigued Redskins coaches, who sought immediate answers about Griffin’s development and the effectiveness of a defense playing without injured starters Brian Orakpo and Brandon Meriweather.

Despite his inexperience, the polished Luck, who ran a pro-style offense at Stanford, presented exactly the type of late preseason challenge that defensive coordinator Jim Haslett wanted. Smart and deceptively quick, Luck impressed in his first two preseason games and he burned the Redskins for a long touchdown pass on a perfect throw. From a pass rush and containment standpoint, though, Haslett obviously had the Redskins well prepared.

After the first-team offense’s poor showing last week against the Chicago Bears, Coach Mike Shanahan and his son, Kyle, the team’s offensive coordinator, wanted to see better timing. That starts with Griffin, who took a step forward against the Colts by making quicker decisions. Griffin still locked on receivers too long at times and needs to improve his accuracy on deep throws.

But he was steadier overall and didn’t take unnecessary chances with his body. He was in better rhythm passing and running. Based on what the Shanahans wanted Griffin to do, it was a net gain for them.

Then there was running back Alfred Morris, who ran even harder and with better results than he produced in his encouraging first start against the Bears. He also made a strong stand in pass protection, which wasn’t the case last week.

Morris is doing everything the coaching staff told him he would have to do to make a move up the depth chart. As coaches are fond of saying: The film doesn’t lie.

With the Redskins set to close the preseason in only a few days (they face the Tampa Bay Buccaneers on Wednesday at FedEx), Shanahan does not plan to have starters play in the last game. The good thing for Shanahan is, he already has seen what needs from the Redskins. Let’s look, too.

Strong signs from Griffin

The Shanahans never expected Griffin to become a finished product in one preseason. They know that would have been an unrealistic goal for him.

When the Shanahans analyze the first two quarters against the Colts, they’ll see that Griffin was in a better grove this week. Griffin’s timing, especially in cycling through his reads in the passing game, was much improved.