Source: Harbaugh was Raiders' top choice; coaching search wide open now

Well, at least the Oakland Raiders tried to hire Jim Harbaugh.

That may serve as small consolation, but a source tells FOX Sports that the Raiders were truly in the mix to sign Harbaugh as their new head coach. Harbaugh, though, ultimately will choose to return to the college ranks as the new head coach at the University of Michigan. That deal could be officially announced as early as today.

"Jim was their first choice," the source said. "(The Raiders) are disappointed."

Harbaugh had previous ties to the Raiders organization, having served as the team's quarterbacks coach in 2002 and 2003. But Harbaugh has an even stronger link to Michigan, which is his alma mater and where he played quarterback during the 1980s.

Harbaugh was released from his San Francisco 49ers contract Sunday night shortly after the team's 20-17 season-ending win against Arizona. Harbaugh's departure ended a year-long saga about his coaching future in San Francisco beyond 2014.

Harbaugh posted a 49-22-1 overall record in San Francisco that included a trip to Super Bowl 47 and three straight appearances in the NFC Championship game. The 49ers finished 8-8 this year and missed the playoffs.

Harbaugh is the second big-name head coach out of the running for consideration in Oakland. Speculation that Jon Gruden would have interest in returning to the Raiders sideline was quashed when he signed a contract extension as an ESPN analyst.

The Raiders (3-13) are expected to interview a slew of candidates to fill the vacancy created after Dennis Allen was fired following Oakland's 0-4 start. Raiders interim head coach Tony Sparano will receive consideration for the position after guiding Oakland to victories in their final three home games.