Alonso’s All-Star bid

When first baseman Yonder Alonso steps in the batter’s box, he seems to have all the confidence in the world.

“His mind-set is so aggressive right now with what he’s going to do,” observed teammate Ryon Healy. “It’s not what he might do, it’s what he’s going to do, and I think that’s something that a lot of the greats in the game have.

“You talk to a guy like (Washington’s) Daniel Murphy, and he’s not hoping to get a hit. He knows he’s going to get a hit. That’s special, and that’s something Yonder has right now no matter if it’s an 0-2 count or 3-0 count.”

Alonso, who’s hitting .299 with a .399 on-base percentage

and .688 slugging percentage, reached base four times Saturday with two hits and two walks and blasted his 16th home run in the A’s win over the Nationals at the Coliseum. His seven previous seasons, he never reached double-digit homers.

The momentum continues to build for his first All-Star assignment. In the first week of fan voting, Alonso ranked second behind Detroit’s Miguel Cabrera.

“I know there’s some time left, but you look at the numbers, it’s usually a tough position

to crack for the All-Star Game, as there’s many good hitters at that position,” manager Bob Melvin said, “but he’s a plus defender on top of it, and he continues to hit homers — and big homers.”

Briefly: After the game, A’s officials had Austin Beck take batting practice as part of a predraft workout, and he smoked several pitches well beyond the outfield wall. The North Carolina high school outfielder is expected to be a high pick in the June 12 draft. The A’s select sixth . ... The A’s made three errors to increase their majors-leading total to 58. ... Reliever Sean Doolittle, who threw 18 pitches for Class A Stockton on Friday, will pitch again for Stockton in the next couple of days . ... Washington’s Bryce Harper completed his three-game suspension for his part in Monday’s brawl at AT&T Park and will return for Sunday’s series finale.