DETROIT – Matthew Stafford may drop back and loft a pass to Calvin Johnson for the last time on Sunday afternoon at Ford Field against the San Francisco 49ers.

The Detroit Lions have invested a lot in Stafford and Johnson, banking on them being a winning combination. The floundering franchise hasn’t gotten much of a return.

Sure, the superstar receiver and inconsistent quarterback have combined to break records and draw cheers. The Lions, though, haven’t had much success as a team with them. Perhaps with a new general manager and coach this offseason, Detroit’s decision makers might choose to manage the salary cap by possibly parting ways with either or both of them.

As Detroit (5-9) prepared for its home finale against the 49ers (4-10), Johnson and Stafford acknowledged they don’t know if Sunday will mark their final game in the Motor City wearing Honolulu blue and silver uniforms.

“Whether it is or whether it is not, just going to go out here and try to leave a great impression,” Johnson said.

Detroit, which drafted Johnson No. 2 overall in 2007, signed him to a $132 million deal in 2012 that could keep him under contract through 2019. In the same year the player known as Megatron signed that contract, he surpassed Jerry Rice’s single-season record with 1,964 yards receiving.

Stafford was selected No. 1 overall in 2009 and was voted NFL Comeback Player of the Year two years later after bouncing back from an injured-filled start by throwing for 5,000-plus yards. He attempted an NFL-record 727 passes in 2012, connecting with Johnson 122 times. This year, he reached 25,000 yards passing in his career quicker than any player in league history. Stafford signed a $53 million, three-year extension two years ago that potentially keeps him under contract through 2017.

Stafford said he has thought “very little” about perhaps playing his last home game as Detroit’s quarterback, adding he is going to enjoy throwing to Johnson as long as he can.

Lions cornerback Darius Slay refused to ponder the franchise’s future without the dynamic duo.

“I can’t picture that, and I won’t picture that,” Slay said.

Here are some other things to watch when the Lions host the 49ers:

CATCHING A MILESTONE: San Francisco receiver Anquan Boldin is a reception away from becoming the 13th NFL player with 1,000 career catches. Boldin’s career got off to a great start in 2003 with Arizona against Detroit, which allowed him to make his debut with two touchdowns, 10 receptions and 217 yards that stand as his personal best. The 6-foot-1, 220-pound Boldin went on to play for Baltimore, where Lions coach Jim Caldwell was once his offensive coordinator, and the 13-year veteran has proven he can still make plays with a lot of strength and some speed for San Francisco.

FAITH REWARDED: The Lions raised eyebrows when they selected Ezekiel Ansah with the No. 5 pick overall two years ago, shortly after he learned how to put on a football uniform at BYU. “The target and expectations were put on me when they drafted me,” Ansah recalled.

He has exceeded the team’s high hopes. Ansah has 13 1/2 sacks, trailing only Oakland’s Khalil Mack, and is two sacks away from breaking Robert Porcher’s single-season franchise mark.

MARQUEE MATCHUP: One of the NFL’s best linebackers, San Francisco’s NaVorro Bowman, and top pass-catching running backs, Detroit’s Theo Riddick, will likely get a chance to show what they can do in space. Bowman is tied with Indianapolis’ D’Qwell Jackson with an NFL-high 136 tackles. Riddick leads the league’s running back with 69 receptions and ranks second among his peers at the position with 605 yards receiving.

ROAD WOES: San Francisco finally won its first road game Dec. 6 at Chicago in overtime following an 0-5 start away from Levi’s Stadium. The 49ers flopped the very next Sunday in a 24-10 loss at Cleveland that included them giving up a franchise record-tying nine sacks.