Quarterback is one of the surest positions on the Patriots roster. Tom Brady is the unquestioned starter, and as the best quarterback in football, that doesn't seem like changing any time soon. Brady is 35, so the team has to have one eye on his replacement despite him signing an extension.
Whilst Brady can never really be replaced, the team has to ensure that the team can succeed if Brady goes down injured, much like he did in the opening game of the 2008 season and Matt Cassel was forced to deputise in his absence. Teams usually go one of two ways in regards to their back up quarterback - they either enlist a veteran who no longer has the talent to start but is capable of efficiently running an offence given tools around him or they draft a signal caller out of college and mould him into the perfect back up and possibly the eventual starter.
With the 74th pick of the 2011 NFL Draft, the New England Patriots selected Ryan Mallett. Mallett had shockingly slipped into the third round amid serious questions surrounding his off-field behaviour, but the Patriots saw value in the Arkansas man, later saying he was the best QB in the entire draft. Mallett has worked his way up the depth chart, after originally being low down in third behind Brady and Brian Hoyer, but after some quality pre-season play and the release of Hoyer, Mallett officially became Brady's number 2.
Mallett, currently is the unstable cog in the quarterback position as trade rumours refuse to go away as all the doubts about Mallett's personality have evaporated after a quiet two years in New England. It's hard not to like Mallett's upside, but if the Patriots receive a first round pick, they'd be foolish not to jump as Brady has many years left yet. It would be surprising if Mallett did leave at this point, however, as he has had very little game time and it's hard to evaluate players in pre-season games. With teams unlikely to give up a first round pick for an inexperienced prospect, it's most likely Mallett stays with the Patriots for another year at least and continue to develop under the stewardship of Brady and Josh McDaniels.
The third quarterback on the Patriots roster is Mike Kafka, someone who is probably unfamiliar to the majority of Pats fans. Originally drafted by the Eagles in 2010, he was released last off-season after the drafting of Nick Foles and having failed to impress Andy Reid and the rest of the coaching staff. Kafka projects to be a back up at best and is a far inferior talent compared to Mallett. Kafka doesn't have particularly good college production, and a tendency for throwing interceptions, but the Patriots were interested around the time of the draft so they seem to see a development player with potential. If circumstances work in Kafka's favour, he could end up being Brady's back up, but his best bet is that the Patriots decide to keep three quarterback's on the roster, or else he could be looking for a new place of work.
Overall, the Patriots are pretty secure at quarterback, as their starter is going to be there for years to come. The biggest doubt comes in the form of Ryan Mallett and if a trade offer comes in for him, but most signs point to the Patriots keeping their top two quarterbacks from last season on the roster.