The afternoon began encouragingly for Zack Greinke. It ended not long after. Just as Greinke had gone about easing one concern, another one popped up.

Greinke departed Wednesday’s game against the Cincinnati Reds with right groin tightness. The severity of the injury is not yet known, but if it’s anything other than a minor issue his status for Opening Day is likely in jeopardy.

For the past week, Greinke had been dogged by concerns about the quality of stuff – concerns he himself expressed to reporters. In an intrasquad game last Thursday, his fastball topped at 87 mph. The previous week it had topped at 86. Greinke wondered aloud if his arm would be ready for the start of the season.

GAME DAY: Updates from Diamondbacks games

But he quickly put those concerns to rest in the first inning against the Reds on Wednesday. His second pitch of the game was clocked at 89 mph. Later in the inning he hit 92 mph. He also recorded a pair of strikeouts, including getting Joey Votto – one of baseball’s best hitters – on an awkward, off-balance swing at a change-up.

The good vibes did not last long. As the Diamondbacks batted in the bottom of the first, right-hander Albert Suarez began warming in the home bullpen at Salt River Fields. When the second inning began, it was Suarez who went out to the mound. Greinke returned to the clubhouse.

MORE: Diamondbacks’ Shelby Miller encouraged by mound session