Hill is the Lions' primary backup to starting quarterback
Hill gave the Lions such good service the last two seasons that he was re-signed in the offseason for two more years. But despite him winning games and providing a steady presence of support for Stafford, the less the Lions see of Hill on game day, the better.
"There's a reason that we acquired him a couple years ago, and there's a reason that we worked hard to get him back under contract," coach Jim Schwartz said. "He was a priority for us.
"The thing that you hope the most with Shaun is that he never gets the chance to prove that."
No knock on Hill, but the fact of life for a backup on a team with a franchise quarterback of Stafford's ability is that the roles are clearly defined. There are no weekly guessing games over who'll start.
The three-ring quarterback circus featuring the Joey Harrington-Mike McMahon, Harrington-Jeff Garcia and Daunte Culpepper-Dan Orlovsky battles chugged out of town long ago.
Stafford is the ringmaster, and that's fine with everyone – including Hill. He understands the role he signed on to play in Detroit.
"Obviously, I know I'm Matthew's backup," Hill said. "I have to prepare every week as if I'm going to play. You always have to be ready, but I know on game day and even throughout the week, I'm trying to help Matthew as much as possible.
"I accept my role. It doesn't mean I'm relaxing in my role. I still try to improve every day, but I do accept where I'm at."
FOX network analyst and former Ravens coach Brian Billick gave Hill high praise in last week's Lions-Ravens game, calling him the best backup in the league.
"Was Mom the broadcaster?" Hill joked when Billick's comment was relayed to him.
"That's very nice of him to say. I don't know how you measure that. I try to be the best at my job that I can."
Being a backup requires a delicate touch – and often the backup is not all that delicate.
A backup with his own agenda can create a toxic environment among the quarterbacks, and it can infect an entire team.
Sometimes, it can be created by coaching or management, as the headline-seeking Jets have done by acquiring Tim Tebow to compete with Mark Sanchez.
In Detroit, Harrington's already-shaky status was further weakened in 2005 when former head coach Steve Mariucci brought in Garcia, his pet quarterback from their days together in San Francisco.
Even something as harmless as a comment can hurt a team.
That happened last year, when the Eagles added to a deep talent pool by signing Vince Young as Michael Vick's backup.
Young, whose career has flopped since being the first quarterback drafted in 2006, called the Eagles "the dream team" at his introductory press conference. The comment was never forgotten, and the season was a nightmare as the Eagles struggled to an 8-8 record.
Hill understands the dynamics of quarterback relationships as well as anyone.
He made the Vikings' roster in 2002 as an undrafted rookie out of Minnesota. He spent five seasons in the league – four with Minnesota, one with San Francisco – without throwing a pass in the regular season.
He started getting playing time with the 49ers in 2007 and started 16 games in a three-year period and performed well, with a 23-11 ratio of touchdowns to interceptions and a 10-6 won-lost record.
The Lions acquired him in a trade with the 49ers in 2010.
"I've been in about every kind of situation you can be in," Hill said. "I've competed with good friends to be the starter or backup, competed to be on teams for years and years.
"Never have I made it a toxic situation. The team is much bigger than any one player, and I certainly don't ever want to bring any kind of negative aspect to the team.
"I see my role the other way -- making sure I help keep some of the negativity out and bring some levity. And always working hard."