ANAHEIM — The A's won't be naming their starting pitcher for the first game of the playoffs until this weekend at the earliest, and manager Bob Melvin said the club has plenty of time to work out various permutations of the roster.

What the club does know is that after ending the season Sunday in Seattle, the club will give everybody the day off, then begin workouts starting Tuesday.

Somewhere in there the A's might have either an intrasquad game or a simulated game to make themselves ready for the first game of the playoffs.

The A's don't know who they will be playing, although they do know they are close to clinching the home field advantage for the first round of the playoffs. A couple of wins, a couple of Tigers' losses or one of each would have the A's at home for the first round.

Talking before Tuesday's game, Melvin said that not all roster decisions had been made, although he jokingly allowed that team home run leader Brandon Moss had made the roster. The A's almost certainly will go from five starting pitchers to four, and the club will have to decide if that means adding a starter to the bullpen or having a starter replace someone in the bullpen.

And a decision has to be made on whether or not to carry three catchers, as the A's have been this month.

Other than saying ``those are possibilities,'' Melvin won't tip his hand, although he did say having catcher Derek Norris work out at first base won't impact the way the catching situation is handled.

-- Norris started taking grounders at first regularly the last two days after Melvin called him into his office Monday afternoon to ask him to take on first base. The club's only right-handed hitting first baseman, Nate Freiman, is out with abdominal pain.

Norris was asked about the huge smile he was wearing when exiting Melvin's office.

``It was exciting,'' he said. ``It's not every day you get news like that. I have no idea where it goes from here, but if I can do something to help the team and get in the lineup, I'm more than willing to get my feet wet there.''

For his part, Melvin said he hoped he wouldn't have to use Norris at first at all. If Freiman, who took some swings off a tee for the first time Tuesday, can play, the manager seems to feel that's the club's best option for right-handed offense at first base.

Still, the manager likes what he's seen from the catcher playing at first base.

``You wouldn't necessarily know it to look at him, but he's a pretty good athlete,'' Melvin said. ``He runs pretty good, too. I'm hoping we don't have to (use him there).''

Freiman could get in some regular batting practice in the cage this week, and if that goes well there's still a chance for him to make the postseason roster.

-- Catcher John Jaso went 1-for-2 with two walks in four plate trips in his first instructional league game Tuesday.

Jaso is hoping to come back from missing more than two months because of concussion problems. It's not at all certain that he will be cleared to play, at least for the first round, but if he is, he would be limited to a designated hitter/pinch hitter role.

While Jaso will spend this week getting playing time with the instructional leaguers, but after that the A's could bring him to Oakland early next week to play in any simulated or intrasquad games.

``There is still time to make decisions of that sort,'' Melvin said. s.

For more on the A's, see John Hickey's Insider at blogs.ibabuzz.com/athletics. Follow him on Twitter at twitter.com/JHickey3.