Embrace the challenge!

That needs to be the battle cry of every Twins fan hoping to find enjoyment in a 2013 season that promises to be jam-packed with challenges.

None of those well-documented challenges — starting pitching, the bullpen, improving infield play at every position other than first base — figures to be more exciting than the ability of the starting corner outfielders to track down balls hit in their direction.

Let’s cut to the chase: Josh Willingham and Chris Parmelee lack speed and range, meaning the starting center fielder better be able to cover a lot of ground.

The newest wave in baseball statistics is finding ways to measure range and defensive proficiency at every position. One of the newer numerical measures combines a variety of statistics to measure runs saved.

A year ago then-Twins center fielder Denard Span was a plus-20 when measured against what the average outfielder would save, according to statistics compiled by Baseball Info Solutions. Span’s rating was the third-best figure among American League outfielders. Ben Revere, the starting right fielder last season, was a plus-9, the 11th-highest ranking in the AL. The Twins traded both Span and Revere during the offseason for much-needed pitching.

The short-term effects of those trades will be, uh, challenging. Willingham, last year’s starting left fielder, returns, along with his minus-15 rating that tied him for 146th among 149 AL outfielders. Parmelee, in limited outfield playing time, compiled a minus-1, which would have computed to a minus-9 had he played 1,200 innings.

Willingham has proved capable of catching most balls hit at him. Parmelee played a fair amount of outfield in the minors, and one year was charged with five errors in 33 games, an alarmingly high total if prorated over 162 games.

So, an opposing batter hits a line drive — no, make that a fly ball — down either foul line.

Embrace the challenge!