That's where Moss -- hitting .283 with a team-leading 13 RBIs -- must remain at least one day but no more than three days, and manager Bob Melvin said the club is expecting him to make the charter flight to Tampa on Thursday's off-day in preparation for the team's weekend series against the Rays.
In the meantime, Peterson, 25, hopes to make the same kind of impression on the big league folk that he did in Spring Training last month, when he compiled a .408 average. In 11 games with Sacramento, he was batting .410 with five doubles and seven RBIs.
"I feel good," Peterson said. "I tried to make sure I was ready to go in Spring Training. I didn't want to use that as an opportunity to get ready. I wanted to already be ready, and I'm just trying to have the same success I had there and carry that into the regular season."
While he went 0-for-4 in his big league debut, Peterson contributed with a key defensive play, robbing Houston's Rick Ankiel of a bases-loaded hit with a diving catch to end the top of the third inning in the A's 4-3 win.
"To come up huge in that situation, to make that play, that's the play of the game right there, not to take anything away from [Josh] Donaldson's [go-ahead RBI] triple [in the eighth inning]," starter A.J. Griffin said. "But that play's huge, kept us in the game and allowed me to keep going."
Peterson, was with the A's less than two weeks ago in Houston, but only because of a false alarm, with Moss back in the Bay Area when his wife went into labor early. Moss returned the next day, and Peterson was never placed on the active roster.
His parents, Southern California natives Brad and Sue, were in Houston in the event their son got an opportunity to play, and they made the seven-hour drive on Tuesday from Temecula, Calif., near San Diego, to see that happen.
"Obviously last time I was up here, I was hoping to get an opportunity and things didn't work out, so I'm just excited to be back again," said Peterson, who has more than 500 Minor League games under his belt. "I'm trying to go out there and not do too much, not get too excited or too amped up and just keep doing what I've been doing the last couple of weeks.
"For me right now, I'm just trying to soak it all in and make sure that this is a great experience. A lot of people don't get this opportunity, so I'm just trying to be thankful for that and go out there and do the best I can and play the type of baseball I've been playing all my life."
Peterson has played almost exclusively in the outfield the past two years in the Oakland organization, appearing at first base just one time last year and again on Monday. But it's his natural position and he's been taking plenty ground balls there in the past few weeks in anticipation of a potential promotion.
"This is everybody's dream," Peterson said. "If it would have taken me 500 games, five games, 5,000 games, whatever it is, it means a lot to be here and get this opportunity. Who knows how long it's going to be, but that's something I try not to worry about."