SCOTTSDALE, Ariz. — The back issues keeping David Dahl off the field and in the training room during spring training are more serious than the Rockies first thought.

Manager Bud Black confirmed Friday morning that Dahl could be out much longer than the club originally anticipated.

“We first said David would be out a couple of days, but it’s going to be longer than that, for sure,” Black said. “I don’t have a timetable on it, but it could be a week or two. There are some things going on with his back. David is undergoing some tests, and scans, and treatment to see what is going on. Related Articles March 3, 2017 Miguel Castro — stronger, more poised — looking for rebound year with Rockies

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“We do think he’s going to be fine, but it’s going to take longer than we first thought. Like I said, we don’t have a real timetable on this.”

Dahl, the promising rookie outfielder, is competing for the starting job in left field with Gerardo Parra. He has played in two Cactus League games this spring, going 0-for-4 with a walk. Dahl was a late scratch from Monday’s game due to his sore back. He has not practiced since then.

The 22-year-old hit .315 with seven home runs in 63 games last season.