But Wellemeyer fired a fastball that Jeter missed. Plain ol' fastball.
"That is keeping it simple," Wellemeyer said.
That was pretty much the formula forced upon Wellemeyer from the get-go. After all, he had to replace De La Rosa with no warning.
De La Rosa was working on 5 2/3 innings of scoreless ball with two runners on base in the sixth. In the dugout, manager Buddy Bell saw something that concerned him.
"I noticed he was starting to look at his finger and wiping his finger on his pants," Bell said.
De La Rosa had developed a blister on the middle finger of his pitching hand. It hurt and it was numb and he was brought out of the game.
Trainer Nick Swartz cut off part of his fingernail but De La Rosa insisted it'd be OK.
"I think I'm going to make my next start," he said.
That might be a bit optimistic, especially to observers of former Royals lefty Jeremy Affeldt's long battle with a similar problem.
Anyway, Wellemeyer had to trot in from the bullpen for a long emergency warm-up.
"You're throwing about 25 pitches and the whole Yankee bench is watching to see what you throw," Wellemeyer said. "So you try to keep it simple."
With De La Rosa leaving two runners on, Wellemeyer struck out pinch-hitter Jason Giambi to end the sixth. Then he got Jeter in the ninth-inning jam to get his first save this season.
For a time, this game was eerily reminiscent of Monday night's debacle, when the Royals also took a four-run lead. That one turned into a 12-5 Yankees victory as four relievers imploded.
Would this four-run advantage really last?
Emil Brown's leadoff home run in the sixth ended Yankees starter Mike Mussina's evening. He would have no shot at his 16th career win over the Royals.
The Royals got two runs in the fourth after singles by Brown, Ryan Shealy and Shane Costa loaded the bases. John Buck rolled into a double play for one run, then Andres Blanco blooped a single to left for another.
The scoring started in the first inning as Mark Grudzielanek singled and fled for home on Mike Sweeney's two-out double.
The 4-0 lead increased to 5-0 against rookie reliever Sean Henn in the seventh. Blanco doubled and scored on Grudzielanek's sacrifice fly.
But no disaster lurked on the horizon. Instead the Royals shut out the Yankees at Kauffman Stadium for the first time since 2003 when Kevin Appier got the win.
"It was a great night," Bell said, "especially after the way things ended up last night."