According to a Dallas Morning News report, Manziel tweeted, "Bulls--- like tonight is a reason why I can't wait to leave college station...whenever it may be.
The post was deleted shortly thereafter but was followed up by what appeared to be a related tweet. It read, "Don't ever forget that I love A&M with all of my heart, but please please walk a day in my shoes."
It's uncertain to what Manziel's initial tweet referred. A Texas A&M spokesman said he doesn't anticipate any response from Manziel on the matter.
CBSSports.com reported Monday that an A&M coach checked in with Manziel and reported that the quarterback understands the strength of his words.
Earlier this week, Texas A&M coach Kevin Sumlin was asked about the constant attention Manziel has received during the offseason. Since Manziel won the Heisman Trophy in December, his profile has risen dramatically.
"I've seen it, just like everybody else," Sumlin said Thursday. "I think being around other guys in the past has helped me, but there's never been anything like this before. Being around Adrian Peterson or Jason White or Sam Bradford or Case Keenum or Drew Brees, people like that, that's part of the deal. When you are a nationally recognized person, whether you're young or a freshman or an older guy, there are some things that come with that.
"Like I said before, (Manziel) is still himself, and he has made some mistakes and he knows that. That's part of growing up. I think, like I've said before, we've got a support process that's in place for him and his family and I know that ever since summer school started he has been back hard at work and he's happy to be back with his teammates."
In late March, Manziel stopped tweeting from his account, telling ESPN.com that social media "can get to be distracting at points." He resumed tweeting from his account on April 12, posting regularly.
As of Sunday afternoon, Manziel had more than 361,000 followers on Twitter and has tweeted 3,562 times.
The quarterback led the Aggies to an 11-2 season and their highest end-of-season ranking (No. 5) since 1956. He compiled an SEC single-season record 5,116 total offensive yards (3,706 passing, 1,410 rushing) and 47 touchdowns en route to becoming the first freshman in college football history to win the Heisman Trophy.