Tension exists between Tom Brady and the New England Patriots' coaching staff, and multiple sources told ESPN that they believe it could influence whether the quarterback finishes his career with the team that he has led to three Super Bowl titles.

Two sources told ESPN that former rookie quarterback Jimmy Garoppolo was drafted as Brady's successor and the move could happen "sooner than later." No source suggested that "sooner" would mean a change during the 2014 season.

Much of Brady's frustration relates to the downsizing of the Patriots offense that stems from questionable personnel decisions and the retirement of longtime line coach Dante Scarnecchia after the 2013 season, the sources told ESPN.

After Sunday's 43-17 win, Brady refuted the notion there were issues between him and the Patriots' staff.

"I love all those guys, my coaches,'' Brady insisted. "I've never had any tension with them, truthfully. It's unfortunate that some things get said and talked about, especially when they don't come from me, and I think that's the -- when you're in the middle of an especially tough week with our team to deal with things that are really outside football that are very personal -- very personal relationships that I've built up for a long time.''

With Pro Bowl guard Logan Mankins being traded before the season, the line now coached by Dave DeGuglielmo is so inexperienced that Brady's input into game plans, personnel groups and pre-snap adjustments has significantly diminished.

One team source told ESPN that a conservative approach is necessary and said everyone needs to be patient to allow the team and staff to get on the same page. Brady's declining performance also has been cited internally, a source told ESPN.

Patriots team president Jonathan Kraft acknowledged some "internal frustration" over the team's start when asked about Brady prior to Sunday night's game against the Cincinnati Bengals.

"We haven't played well. We haven't played well all year," Kraft said during a radio interview with 98.5 the SportsHub. "So I think there's that type of unhappiness, an internal frustration makes you want to overcome it.

Tom Brady may not finish his career in New England because of tension between the star quarterback and the Patriots' coaching staff, according to sources. Dilip Vishwanat/Getty Images

"But I haven't seen any despair or finger-pointing or anything like that. And look, we are 2-2. It's the quarter point of an NFL season. There's an awful lot that is going to happen."

Nevertheless, the circumstances have affected Brady's confidence and performance, sources told ESPN, and the Patriots have had little success providing the talent needed to execute the team's previous approach -- a complex scheme that can change dramatically on a weekly basis.

The team's draft history also is under fire. The Patriots have used 11 draft picks on receivers since 2002 and only two -- Deion Branch and former college quarterback Julian Edelman -- have made any impact. The signing of Danny Amendola as a slot-receiver replacement for Wes Welker has proven to be a failure, too.

Even though Patriots coach Bill Belichick chuckled when asked Monday night about Brady's status, more than one source told ESPN that "nobody is untouchable."

Brady has stated publicly he wants to play another four or five years, at least. Sources close to the quarterback told ESPN that remains true but acknowledge that his career may end with another franchise unless Patriots owner Robert Kraft intercedes.