"That's probably a fair assessment," said Macha, when he was asked about Johnson on Wednesday.
Johnson has found his swing again for the River Cats and is hitting .307 in 44 games, with seven homers and 44 RBIs. Macha doesn't anticipate that Johnson will get a great deal of playing time, but the left-handed hitter could fill in at first base if Macha wanted to move Nick Swisher to the outfield.
"It would give us an opportunity to have another power hitter in the lineup if we come into a problem like we did today [with Bradley]," Macha said.
But what Macha is more concerned about is another backup shortstop. Bobby Crosby is on the disabled list with back problems for the second time in a month, and Marco Scutaro has been a good substitute for most of August.
"Scut's been great," Macha said, "and he's been very durable, and if something happens to him and Crosby doesn't come back, we're in a little bit of a problem."
The most likely choice would be River Cats shortstop Mike Rouse, who played with the A's earlier in the season when Mark Ellis was on the DL. Rouse had 24 at-bats in June and hit .292 with three hits in his Major League debut against the Yankees.
Baseball/football field: The Oakland Raiders played two preseason games at McAfee Coliseum before the A's current nine-game homestand and left some thin grass and a number of brown spots in the outfield.
A's outfielder Jay Payton, who has played in all three outfield positions during the three-game series against the Red Sox, said he had to take a different approach in what is left of the outfield grass.
"The field is just faster," Payton said. "You know when a ball is hit in the gap, if you don't get there it's going to get by you. Depending on the situation of the game, you might want to play a little deeper.
"[The field is] hard, there's not really any grass. It's like hard dirt that has spray paint on it. We're probably going to get a bad hop every now and then, but it's a situation that both teams have to play with, so I don't let it affect me."
Crow hops: With Bradley out of the lineup, Macha moved Swisher to the No. 2 spot and Mark Kotsay in the three hole. Kotsay came into Wednesday's game batting .300 against Red Sox starter Curt Schilling, but Swisher was 1-for-8. Macha joked before the game, saying that Swisher was due, and that Swisher wasn't looking for revenge after getting plunked in Boston on a Schilling inside fastball. "It increased his on-base percentage and that's what we're worried about here, right?" cracked the A's skipper. In Swisher's first at-bat, he struck out for the 123rd time this season and became a part of history by being the 3,000th K for Schilling. ... Macha said that closer Huston Street did agility drills before Wednesday's game and threw on the side. The next step for Street, who is on the DL with a strained right groin, is to throw again on Friday after being evaluated by the training staff on Thursday. ... Rich Harden, who is on the DL with a sprained ligament in his right elbow, threw before Wednesday's game under the supervision of trainer Larry Davis. The A's are hoping that Harden will be able to throw from halfway up the mound during the weekend series against Baltimore.
Up next: After an off-day on Thursday, the A's will open up a weekend series against the Orioles. Righty Joe Blanton (14-10, 4.45 ERA) is slated to start at 7:05 p.m. PT on Friday against lefty Erik Bedard (12-9, 3.92).