The Yankees remained four games behind the AL East-leading Blue Jays but lowered their magic number for clinching a wild card to three with their 6-1 victory over the White Sox on Sunday at Yankee Stadium.

Luis Severino pitched six shutout innings and made himself part of the conversation about the starter in the wild-card game amid the uncertainty of Masahiro Tanaka's hamstring injury, although Joe Girardi has other alternatives.

In football parlance, this would be something of a quarterback controversy that Girardi wants no part of. Asked if he'd be comfortable with Severino if Tanaka can't go, he said: "That's a hypothetical. I think Tanaka's going to be fine, so that's not too much of a concern of mine. But [Severino has] pitched extremely well and we have a ton of confidence in him."

Tanaka has been a mostly effective but oft-injured ace in his first two seasons. Severino is the healthy, raring-to-go Triple-A call-up deemed untouchable for trade at the non-waiver deadline.

Tanaka hasn't pitched since Sept. 18, when he suffered what the Yankees said was a Grade 1 hamstring strain while running to first base against the Mets. Tanaka always says he's good to go, but Girardi has not scheduled a tuneup that would line him up for the wild-card game a week from Tuesday at Yankee Stadium.

"I know everyone wants an answer, but it's not that simple because of his value to us," Girardi said. "It's something you have to weigh. Is it worth the risk, you know, maybe moving it up a day or two days if you need him? It's a careful situation that we're trying to manage."

advertisement | advertise on newsday

Asked Sunday how he feels, Tanaka said through his translator: "Very good . . . It's getting better and better. It feels good."

He would not discuss the wild-card game, saying: "I don't think we're there yet. I'm not ready to talk anything about that yet. As for now for me, I'm just happy with the way I am progressing."

He also said he has not been told when he might pitch this week and added, "That's something that's not my decision."

Girardi set a Thursday deadline for Tanaka to pitch once more in the regular season. That would give him four days' rest before the wild-card game.

Severino, who apparently didn't get the memo to remain mum on the wild-card issue, said he would be ready if asked. "I would be happy to, of course," he said.

Yankees videos

And the 21-year-old wouldn't be overwhelmed? "Of course not. I'd be happy to start," he said. He added that he has not been told when his next start will be.

Brian McCann wasn't surprised at Severino's readiness to pitch the wild-card game. "Everyone in here already knew that," he said. "We get to watch him, be around him on a daily basis. He's an impressive pitcher."

Severino (5-3, 2.77) allowed five hits and a walk and was helped by four double plays, one on a strikeout-caught stealing. "He was throwing fastballs both sides of the plate," McCann said, "[and] throwing the slider to both sides of the plate and kept them off balance with a changeup."

The Yankees were 3-for-19 with runners in scoring position and stranded 15 baserunners -- five on third and five on second -- but it didn't matter.

McCann hit a sacrifice fly in the first inning after consecutive errors by first baseman Jose Abreu loaded the bases with none out. They added two in the sixth on Dustin Ackley's homer into the second deck in rightfield and a two-out passed ball. Jacoby Ellsbury's two-out RBI single made it 4-1 in the seventh and the Yankees got two in the eighth on Greg Bird's RBI single and Slade Heathcott's sacrifice fly.With Roger Rubin