Robert Griffin III (10) pats Ryan Grant on the helmet after a preseason touchdown catch against the Bucs. (Toni L. Sandys/The Washington Post)

Rookie wide receiver Ryan Grant impressed coaches with his smarts at the combine.

During Washington’s rookie minicamp, he impressed with the professional way he went about his job, with Coach Jay Gruden likening him to “a 10-year veteran.”

Throughout training camp, Grant impressed all three of Washington’s quarterbacks with his precise routes and sure hands.

And if there was any doubt about his place on the 53-man roster, Grant erased it with his performance in the preseason finale at Tampa Bay, in which he caught five of the six balls thrown his way by third-string quarterback Colt McCoy — including a 2-yard strike for this second touchdown of the preseason.

“He’s just really good; I really believe he’s going to be a difference for us this year,” gushed McCoy, who played the entire game, completing 22 of 29 passes for 321 yards, with two touchdowns and two red-zone interceptions.

A fifth-round draft pick from Tulane, Grant was targeted frequently in all four preseason games.

He finished with a team-high 14 catches, for 165 yards and two touchdowns, which tied for fourth among all NFL receivers through the preseason.

His 14 receptions trailed only Arizona’s Britten Golden, Philadelphia’s Jordan Matthews and Buffalo’s Robert Woods. They tied Jacksonville’s Allen Hurns’ 14.

In addition to scoring on the 2-yard throw from McCoy, Grant caught a 14-yard strike from Kirk Cousins against Cleveland.

At 23, Grant may be the youngest and least experienced in Washington’s six-man wide receiving corps, which is anchored by DeSean Jackson and Pierre Garcon, who had 195 catches between them last season.

He’s not the fastest of the bunch, either. But he has qualities quarterbacks love.

As McCoy explains: “He doesn’t drop balls, and he’s a real friendly target for a quarterback. Some guys are super fast; some guys can adjust to the ball really well. They all have unique things. But for Ryan, he’s just consistent. And as a quarterback, you’ll take a consistent guy over anybody else — guys who you know are going to be in the right spot.”

McCoy cited the successful fade route into the end zone against Tampa Bay early in the third quarter.

“I put the ball where only he could catch it, but not a lot of guys are going to make that play,” McCoy said of Grant. “I have a lot of confidence in him; I know Robert [Griffin III] does, too. I’m excited about his future. The guy just gets better and better every day.”

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