Hensley, 34, last pitched in the big leagues in 2012, when he posted a 4.62 ERA in 60 games spanning 50 2/3 innings.
Last year, Hensley split his time on a mound between the independent Sugar Land Skeeters and two Triple-A affiliates (of the Reds and Brewers). He pitched to a 0.63 ERA in 14 1/3 innings for Sugar Land, and then allowed eight runs in 20 2/3 innings (good for a 3.48 ERA) at the two Triple-A affiliates.
Hensley has pitched in parts of seven big league seasons, posting a career 28-34 record and a 4.00 ERA.
His best big league season came back in 2010 with the then-Florida Marlins, when he had a 2.16 ERA and a 1.107 WHIP in 75 innings of work.