Diamondbacks' Hill reportedly on the trade block

The Arizona Diamondbacks are entertaining offers for second baseman Aaron Hill, reports Jon Heyman of CBSSports.com.

Hill, 32, is signed through 2016 at a salary of $12 million per year but is enduring one of his most disappointing seasons as a pro. 

The Diamondbacks second baseman owns a career-worst .285 on-base percentage and is experiencing his lowest isolated power rate (.131) since 2011. Hill is striking out more and walking less and his productivity is a far cry from the 26-homer, 44-double and 14-steal campaign that netted him MVP votes in 2012.

Heyman notes that while Arizona is eager to move Hill, the club would prefer to keep infielder Martin Prado.

The 30-year-old is also suffering through one of the worst seasons of his career, but the Diamondbacks appear to value his positional versatility, price (owed $22 million over the next two seasons) and age more than Hill.

Prado is hitting .274/.319/.369 with four homers and 16 doubles this year.