It's not quite Hamlet, but the ghost of Mark Prior can be a significant force in managerial decision-making

...Texas on Thursday, April 9, 2009. The Rangers defeated the Indians 12-8. WASHINGTON - JULY 21: Mark Prior #22 of the Chicago Cubs pitches during a baseball game against the Washington Nationals on July...

CHICAGO - OCTOBER 14: Starting pitcher Mark Prior #22 of the Chicago Cubs throws against the Florida Marlins during Game 6 of the National...

CHICAGO - OCTOBER 8: Mark Prior #22 of the Chicago Cubs throws against the Florida Marlins during game two of the National...

PEORIA,AZ - FEBRUARY 22: Mark Prior #22 of the San Diego Padres poses for a portrait during spring training on February 22...

Fantasy pitchers are an enigma. Mark Prior is no exception

Mark Martin, right, talks with team owner Rick Hendrick prior to the Start of the Chevy Rock & Roll 400 Sprint Cup race...

21 August 2009: Washington Nationals principal owner Mark Lerner (L) talks with agent Scott Boras (R) prior to the game between the Milwaukee Brewers and the Washington Nationals after...

...2009; Knoxville,TN, USA; Georgia Bulldogs head coach Mark Richt on the sideline against the Tennessee Volunteers...Gators head coach Urban Meyer walks the sideline prior to a game against the Mississippi State Bulldogs...

...USA; UFC fighter Lyoto Machida prior to his fight against Thiago Silva during the light heavyweight bout in UFC 94 at the MGM Grand Hotel and Casino. Mandatory Credit: Mark J. Rebilas/US Presswire

...Mark Martin, left, of Batesville, Ark., talks with Dale Earnhardt of Kannapolis, N.C., prior to the qualifying runs for Sunday's Winston 500 at...

ILE -- This is a Sept. 12, 2009, file photo showing Mark Herzlich, left, running onto the field with Boston College head coach Frank Spaziani prior to the start of an NCAA college football game against...

FILE -- This is a Sept. 12, 2009, file photo showing Mark Herzlich, left, running onto the field with Boston College head coach Frank Spaziani prior to the start of an NCAA college football game against...

...Glendale, AZ, USA; Arizona Cardinals wide receiver Larry Fitzgerald prior to the game against the San Francisco 49ers at University of Phoenix Stadium. Mandatory Credit: Mark J. Rebilas-US PRESSWIRE

RICHMOND, VA - SEPTEMBER 12: Mark Martin, driver of the #5 Kellogg's Chevrolet, stands next to his car prior to the NASCAR Sprint Cup Series Chevy Rock & Roll 400...