PITTSBURGH -- William Fowler felt he had finally hit a turning point, which is why, shortly before he took the field in Friday's series opener against the Pirates, he confidently confided in a few coaches.

"Spring Training is over," Fowler told them. Now his season might be, too.

Fowler left PNC Park on crutches, unable to put any weight on his left foot, which he fractured in the eighth inning of the Cardinals' 7-6 loss. He was added to the 10-day disabled list Saturday and will return to St. Louis, where the Cardinals' medical staff will evaluate the severity of the injury. That diagnosis will determine whether there's time for Fowler to heal and return to the field this season.

"It sort of sums up our year in a lot of ways," president of baseball operations John Mozeliak said. "It's unfortunate. And he was actually swinging it a little bit. The timing is not good, and he's certainly bummed."

Fowler traced the injury back to the sixth inning, when he fouled a ball off the top of his foot. Fowler said his foot was instantly sore, though he "didn't think anything of it."

That foot tightened some more in the field, and it continued to nag at him when he swung the bat in the eighth. Fowler slowed up as he raced to first on a force out, then felt a "pop" while running from second to third. Fowler had to be helped off the field.

X-rays taken at PNC Park confirmed a break.

While the Cardinals may eventually bring up another outfielder to enhance their depth, they'll stick with who they have for the remainder of this weekend's series in Pittsburgh. Second baseman Kolten Wong takes Fowler's place on the 25-man roster.

Fowler's injury does pave the way for rookies Harrison Bader and Tyler O'Neill to start alongside each other. Yairo Munoz will serve as the club's fourth outfielder.

"We were talking about giving opportunities to Bader and O'Neill," said Mozeliak, who had just dealt outfielders Tommy Pham and Oscar Mercado from the 40-man roster on Tuesday. "Now, that's real."

Fowler is hitting .180/.278/.298 with eight home runs and 31 RBIs this season.

<p. fowler="">"I just started feeling better at the plate," said Fowler, who went 2-for-4 with an RBI single before exiting. "My timing was there, and this happens. It's disappointing. It sucks. But [I've] got to take the good with the bad. Hopefully, I don't have to get surgery." </p.>