The Rockies also have interviewed Tom Runnells, who became the bench coach when Tracy took over as manager in 2009; free agent first baseman Jason Giambi, who has played with the club since 2009 and would retire if offered the managerial post; and former Major League shortstop Walt Weiss, who spent part of a long career with the Rockies and worked several years for the club as a special assistant.
Manuel, 58, managed the White Sox from 1998-2003, the Mets from 2008-10, and has a record of 704-684 as a manager. In 2000, Manuel earned American League Manager of the Year honors when he led the White Sox to a first-place finish in the AL Central. The Mariners swept the White Sox in the AL Division Series. Manuel took over the Mets from Willie Randolph in 2008, and the club went 55-38 under him while finishing second in the National League East.
Mackanin, 61, was bench coach for the Phillies from 2009-2012. Mackanin also has had two stints as an interim manager -- with the Pirates when he was promoted from bench coach to replace Lloyd McClendon at the end of the 2005 season, and with the Reds when he replaced Jerry Narron during the 2007 season. The Reds had a league-worst 51 losses under Narron, but went 41-39 under Mackanin. The Phillies chose not to renew his contract at the end of the 2012 season.
Both new candidates spent considerable time as Triple-A infielders in Denver. Manuel played in 128 games for the Denver Bears in 1980, and hit .277 with three home runs and 61 RBIs. In 1984, he played in 109 games for the Bears and hit .293 with four homers and 40 RBIs.
Mackanin also had two stints with the Bears. In 1978, he played in 131 games and hit .276 with 17 home runs and 112 RBIs, and in 1982 he hit .268 with 16 homers and 73 RBIs in 116 games.
Other reported candidates for the job include Indians bench coach Sandy Alomar Jr., Padres front-office assistant Brad Ausmus, Athletics third-base coach Mike Gallego, Dodgers third-base coach Tim Wallach and D-backs third-base coach Matt Williams, who is managing some of the Rockies' prospects in the Arizona Fall League.
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.