Source: Reds calling up Dontrelle Willis

The Cincinnati Reds are calling up pitcher Dontrelle Willis from Triple-A Louisville and plan to start him Sunday against the Milwaukee Brewers, a source close to the team told ESPN.com.

Willis, 29, takes the place of Edinson Volquez, who has been optioned to Louisville to work out his control issues. The Reds nearly called up Willis earlier this week when Bronson Arroyo suffered a bout of dizziness during a bullpen session, but Arroyo recovered to make his next scheduled start.

Willis, the 2003 NL Rookie of the Year and a 22-game winner in 2005, has bounced around with several clubs recently. He's been with the Detroit Tigers, Arizona Diamondbacks, San Francisco Giants and Reds organizations the past 13 months.

In 13 starts with Louisville this season, Willis has made significant strides in addressing some longstanding control problems. He's 5-2 with a 2.63 ERA and has 67 strikeouts and only 20 walks in 75 1/3 innings.

The Reds are a disappointing 44-45, thanks in part to inconsistency in the starting rotation. Cincinnati's starters rank 15th among the 16 NL clubs with a 4.63 ERA.

Jerry Crasnick is a senior writer for ESPN.com.