Maryland Coach Randy Edsall said he was “disappointed” with the decision of Danny O’Brien, shown last November against Notre Dame. (Toni L. Sandys/WASHINGTON POST)

What had been expected for days became official Monday: Maryland quarterback Danny O’Brien and two other players — offensive lineman Max Garcia and linebacker Mario Rowson — are leaving the football program.

Maryland will enter next season without the 2010 ACC rookie of the year in O’Brien and without its two starting offensive tackles from this past season, Garcia and R.J. Dill, who chose to transfer earlier this offseason. O’Brien, Garcia and Rowson all were granted their releases from the program, capping an eventful week for the Terrapins.

Three days after landing five-star wide receiver prospect Stefon Diggs of Good Counsel, more current players headed out, bringing to 12 the number of players with eligibility remaining to leave since season’s end. In all, 24 players have left the program for various reasons since Coach Randy Edsall was hired in January 2011.

Among departed players, the most noteworthy is O’Brien, a third-year sophomore who garnered attention because of his play on the field, mostly during Maryland’s 9-4 season in 2010, and because of what those close to him described as his tireless work ethic and appetite for film work.

In a statement released by Maryland, Edsall said that he is “disappointed” by O’Brien’s decision to leave the program and that “Danny told me that he is not committed to our program, that he is not ‘all in.’ I want what’s best for all of our players. Danny wants a fresh start elsewhere. I wish him well.”

O’Brien is expected to graduate after the spring semester, which means he could enroll at another Football Bowl Subdivision school and play immediately, so long as he enrolls in a graduate program not offered at Maryland. Mississippi, Arizona and South Florida are among the schools that have already shown interest in O’Brien, but those close to O’Brien said the process is in its early stages.

One possibility had been Vanderbilt, where James Franklin, the former Maryland head coach-in-waiting, just completed his first season. Franklin’s presence at Maryland was among the primary reasons why O’Brien committed to the school out of high school in Kernersville, N.C.

But Edsall did not give O’Brien his release to transfer to Vanderbilt, according to an individual familiar with the conversation between the coach and player. Another individual that spoke with O’Brien said Edsall would not allow O’Brien to transfer to as many as 16 schools — 11 current ACC schools, future ACC schools Pittsburgh and Syracuse and other future nonleague opponents.

The individual, who spoke on condition of anonymity because he is not authorized by the families to discuss details publicly, added that the stipulations for Garcia and Rowson included the same 16 schools.

One longtime college administrator said Monday that an attempt by a coach to block a player from transferring to a specific school is uncommon only when — as is the case with Maryland and Vanderbilt — the two schools are not scheduled to play each other in the near future.

In a telephone interview, Edsall declined to discuss the details of O’Brien’s release.

Several parents of Maryland players had said since October that O’Brien would seriously consider transferring after the season. But Edsall was taken aback when O’Brien told the coach his feelings during what has been described as a 30-minute, nonconfrontational meeting on Wednesday.

According to someone who spoke with O’Brien, Edsall told O’Brien, “Danny, if you decide to do this, with all you have accomplished here, I think you are making a mistake. Really think this through.”

Edsall and O’Brien agreed to contemplate the potential move through the weekend. On Monday, O’Brien reaffirmed to Edsall his intention to leave.

O’Brien played in nine games — starting seven — this past season before seeing his sophomore year cut short when he broke his non-throwing arm against Notre Dame on Nov. 12. He completed 150 of 266 passes for 1,648 yards with seven touchdowns and 10 interceptions.

Several factors contributed to O’Brien struggling to match his performance from 2010. The offense did not possess wide receivers the caliber of 2010 standouts Torrey Smith and Adrian Cannon, and dropped passes by receivers became an oft-repeated story line in 2011.

Some individuals within the program said O’Brien struggled with reads early in the season and questioned whether O’Brien was the best fit for the up-tempo, spread offense installed by offensive coordinator Gary Crowton, who lasted just one season before being replaced with Mike Locksley.

Now Maryland is down to one experienced quarterback in 2012, the mobile C.J. Brown, who will be a junior next season.