In the locker room before this week's preseason opener, Greg Roman saw what he wanted to see in rookie tight end Garrett Celek.
He witnessed more of the same as the night wore on.
"Liked the look in his eye before the game. He was ready to play against somebody else in a different color jersey," the 49ers offensive coordinator said prior to Sunday's training camp practice. "There's that a faraway eye and there's a steely-eye glare. So I would define his as more of a steely-eyed glare variety."
Looks quickly turned into stats against the Denver Broncos. In his debut, McDonald led San Francisco in catches, four, and receiving yards, 66.
The Rice product was inviting comparisons to former 49ers pass-catcher Eric Johnson on social media. He was brought in as a second-round draftee to fill the cleats of another talented end in Delanie Walker, who departed the organization via free agency this offseason.
McDonald dressed in full uniform for Saturday's "Fan Fest" practice at Candlestick Park but did not participate in team drills and also spectated on Sunday.
Reserves Garrett Celek and MarQueis Gray have picked up the slack in his brief absence, but McDonald's performance Thursday should given him a head-start in any roster competition.
"He graded out pretty well," Roman said of McDonald. "Like anybody else, there were plays that he wished he could have back. But for a good young guy like him, great learning experience."
There's little doubt that McDonald, once healthy, will have an opportunity to improve his blocking, the other main responsibility of any pass-catcher. The 49ers visit the Kansas City Chiefs on Friday in their second of four exhibition games.
"As everything, it's a work-in-progress," Roman said, "but I'm pleased with where he's at and where he's going."