I got this idea from Andrew over at Revenge of the Birds.  We have plenty of discussion about who we like on the 49ers, and who we fear on the opposing team.  However, this post allows us to go off into fantasy-land a bit and decide who we might like from an opposing team.  In doing this, you can approach it from a variety of angles.  You can take a player just because you like that player, no matter what the 49ers current situation is at that position.  You can consider who the 49ers might lose in the offseason or positions they need to improve.  If you want to take into account the player's contract and look for "realistic" additions, you're free to do that.  You can be as realistic or as fantastical (if that's even a word) as you'd like.  For this week, here are some of the guys I'd enjoy having on the 49ers...

Today we're looking at a franchise, the Detroit Lions, that has been struggling most of this decade, with their last winning season coming in 2000.  Given their struggles, it's not surprising that it is rather difficult to come up with four players I'd want.  I'd say the first two are the most obvious selections.  The third is a rookie I'm at least a little intrigued by.  The final one is a guy who is a bit of a homer selection

Calvin Johnson, WR: Amazingly enough, this is the third time we've done this feature, and all three times the first guy I listed has been a wide receiver.  It's safe to say the man they call Megatron (nickname provided by Roy Williams) is the most talented player on the Lions roster.  They've got some other solid players, but Johnson has been the man for them.  Johnson's numbers haven't been spectacular this season (Vernon has better numbers), but he was sidelined with a knee injury, and of course, he's dealing with double-teams.  When your #2 and #3 statistical wide receivers are Dennis Northcutt and Bryant Johnson, I'd imagine teams will be giving your #1 guy a lot more respect.

Even though the 49ers have some solid wide receivers in their stable, adding a beast like Calvin Johnson would certainly help.  At 6-5 236 lbs, there are not many corners who can handle his combination of size and speed.  Having a duo of Calvin Johnson and Michael Crabtree?  Well that would be a thing of beauty.

Louis Delmas, S: Delmas is a rookie out of Western Michigan and has made an immediate impact for the Lions at the free safety position.  He's third among all rookies in tackles, leading rookie DBs.  If the 49ers could roll him into their roster, they could either put him at strong safety, or move big hitter Dashon Goldson over to strong safety.  Whatever the case may be, I have to say that a pairing of Delmas and Goldson would conceivably set up the 49ers at the safety spots for the next decade.  Two young players?  Oh yes I definitely think so.  At this point I've got Calvin Johnson listed at the top, but I would argue Delmas is a close second.  In fact, one could argue him ahead of Megatron given the 49ers own existing needs in the secondary.

Cliff Avril, DE: Avril has yet to break through two seasons into his career, and Lions fans were rather disappointed with his 2009 season.  I suppose I'm looking more at the upside that people thought he might have had back when he was drafted in the third round in 2008.  I know he's in the 4-3 and a bit undersized, but maybe they could slim him down a little bit and move him back to outside linebacker and take advantage of his rather decent pass rushing skills.

Julian Peterson, OLB: Peterson was always one of my favorite 49ers when he was still in town.  He showed amazing versatility, most notably in battling Tony Gonzalez a few years back.  He's on the wrong side of 30, but I believe he can still provide that versatility.  He struggled early on with the Lions but seems to be kind of finding himself in the defense.  I suppose in the end it's more of a fan pick than anything else.  I wouldn't mind seeing him work with Parys Haralson, Ahmad Brooks and Manny Lawson on their skills.