The Milwaukee Brewers recently changed managers and it was reported the club was interested in Pat Murphy, who is the manager for the San Diego Padres' Triple-A El Paso affiliate. However, the Padres refuse to let him go. Why?

FOX Sports' Ken Rosenthal provides a number of potential explanations and rumors, but one jumps out ahead of the rest and it involves manager Bud Black.

"The Padres' 20-20 record is fueling industry-wide speculation that Black could be in trouble," he writes. "Ownership expects to win after opening the season with a club-record $109 million payroll. General manager A.J. Preller is in his first full season, and like ownership, inherited Black."

This is not something to overlook. Black has been with the Padres since 2007. He has amassed a record of 637-700, has only two winning seasons (2007, 2010) and has never reached the postseason with the club. San Diego finished ahead of third place in the NL West division just once over that eight-year span - back in 2010 when they came in second and Black won NL Manager of the Year.

We've already seen the Brewers fire manager Ron Roenicke and the Miami Marlins dismiss manager Mike Redmond this early into the season. Nobody's job is safe.

However, Rosenthal spoke with other sources who reiterated the team's unwillingness to let Murphy join the Brewers' coaching staff has nothing to do with Black's job security.

"...the Padres consider Murphy an 'impact guy,' even though he is only at Triple-A," one Padres official told Rosenthal.

"...the Padres, according to one source, believe that losing their Triple-A manager in the middle of the season would be 'chaotic,' and that if Murphy wants to join the Brewers, he can simply wait until the minor-league season ends in early September," he added.

Nonetheless, some MLB execs view this move by the Padres as "highly unusual," which has led many to believe something is up. That could be the case, but then again, it's possible the Padres are really focusing on cultivating their prospects at the highest minor-league level because they traded so many away this offseason.

Additionally, Murphy has never had a losing record since beginning his coaching career in 1988, according to MiLB.com. He was head coach for the University of Notre Dame from 1988-1994 and then moved on to Arizona State from 1995-2009 before entering the Padres' farm system. He managed short-season Eugene (2011-2012), Triple-A Tucson (2013) and Triple-A El Paso (2014-).

So while Black's job security has entered the rumors, there's no doubting the Padres value Murphy for his success as manager. Whether or not that means he'll be with the MLB club in the near future remains to be seen.