Mariners placed RHP Taijuan Walker on the 15-day disabled list Saturday, retroactive to March 21, with a right shoulder injury. The top prospect developed some mild shoulder inflammation early in Spring Training and the Mariners are being extra cautious to be safe.

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2014 MLB Predictions: AL

2014 MLB Predictions: NL

Walker is expected to rejoin the Mariners by late April and is still the favorite to be the American League’s top rookie starter. The 21-year-old righty was spectacular in the minors last season, posting a 2.93 ERA and 160/57 K/BB ratio over 141.1 innings.

Fantasy baseball 2014 closers report

Walker, arguably the top-pitching prospect in baseball, threw 156.1 innings last season between two levels of the minors and his three-start stint in the majors. He isn’t quite ready for 200 innings, so starting the season on the DL might not be too harmful for fantasy owners in the long run. Walker would have been on a strict innings count this season, with a chance to be shut down late in the year.

Basically, he’s missing a few starts in April, instead of missing time in September. Most fantasy owners would prefer the production later in the season when championships are being determined.

Walker should be drafted in all standard fantasy leagues. He’s an ideal player to stash on a DL spot for the first few weeks of the season. He’s capable of emerging as an top-notch fantasy option immediately and his ceiling is a Jose Fernandez-like rookie ace. He’s an elite commodity in all long-term keeper and dynasty formats.

Questions? Hit me on Twitter @briansflood