Randy Johnson threw across the outfield grass in nearly empty Yankee Stadium to bullpen coach Joe Kerrigan as two other coaches looked on. Having passed the first test, the Big Unit said he'll throw a bullpen session Sunday to prepare his balky back for the playoffs.

One day after receiving a epidural shot to treat a herniated disc, Johnson played catch for seven minutes, then threw eight pitches on flat ground in the outfield.

``My arm felt good, but tomorrow will be the real barometer on how I feel,'' Johnson said. ``And then, obviously, if I get through that, how my back feels on Monday.''

Johnson is scheduled to pitch Game 3 of next week's first-round playoff series against Minnesota or Detroit. Yankees manager Joe Torre also said before the game that Gary Sheffield will be his postseason first baseman, and Jason Giambi will be a designated hitter. That decision means one player won't be able to start from among Giambi, Hideki Matsui and Melky Cabrera.

``It's a lot about his personality that probably helped feeling comfortable with him over there,'' Torre said of Sheffield. ``He's a little more agile in moving around there at this point in time.''

Torre also said Miguel Cairo and Andy Phillips will be on his 25-man roster for the first round, and that Craig Wilson, Aaron Guiel, Nick Green and Octavio Dotel will be left off.

Johnson threw for the first time since Sept. 23, when he gave up five runs and seven hits over six innings in an 8-0 loss last weekend at Tampa Bay. He is optimistic he'll be able to pitch Friday and sounded determined.

``I can win 17 games anywhere, but my better chances to go to the playoff were coming by the Yankees. That's why I'm here,'' he said. ``I'll do whatever it takes. I've pitched through pain and discomfort before. I'm 43 years old. I've got an arthritic knee _ I'll probably need knee replacement when I'm done; I've accounted for that _ I've had one back surgery and another one probably that I may need. I'm not going to complain. I'm here to pitch post-season and I'll do whatever I can. Obviously, I don't want to put the team in jeopardy by not being that effective.''

Johnson was 17-10 with a career-high 5.00 ERA in 33 starts this season. His back lower stiffness began in September and increased throughout the month.

``There's two things that I was dealing with,'' he said. ``I was dealing with the tightness in my back, probably due to the herniation. After pitching in Tampa, I was dealing also with the back spasms, too, and those are probably more debilitating than the pain or the stiffness itself.''

He isn't worried about making the injury worse. If Sunday goes well, he plans to throw another bullpen session Wednesday.

``I don't think there's any more risk,'' he said. ``I suppose I could damage the area a little bit more, but that could always be surgically corrected, I suppose, so let's go for it.''

If Johnson can't pitch, Jaret Wright and Cory Lidle would start Game 3 and, if needed, Game 4. But Torre seems to be anticipating Johnson will be on the mound.

``This doesn't surprise me that he's going to do everything to get out there on Friday. I never had any doubt that was his determination,'' Torre said. ``It's what makes him special.''

Sheffield, sidelined from May 29 to Sept. 22 with an injured left wrist that required surgery, hadn't played first base in the major leagues before his return.

``Coming back, you want to be a part of this,'' he said. ``You want to win the ring on the field. I didn't want to win it sitting down.''

He had a crash course with Yankees hitting coach Don Mattingly, a former Gold Glove first baseman. Sheffield says the toughest part is knowing when to go after balls between himself and second baseman Robinson Cano and when to hold the bag. Cutoffs have been a learning experience.

``I didn't know it was going to be as much work or that complicated,'' he said. ``A lot of times I forget to go over there, but then when I think about it, I sprint over there and get there in time.''

As for left field, Torre said earlier in the week he might opt for defence over run production, which would give the nod to Cabrera. But it's also hard to overlook Matsui's bat.

``I'm very comfortable with Hideki in left,'' Torre said Saturday.

Notes: Torre planned to let Bernie Williams manage the Yankees on Sunday in their regular-season finale against Toronto. He wasn't sure whether Mariano Rivera or Mike Mussina would serve as the pitching coach for Williams, who might retire after this season.

© The Canadian Press, 2007