The joint practices between the Ravens and 49ers wouldn't be happening if it weren't for John and Jim Harbaugh, who both love the challenging atmosphere the sessions will create. But just because the brothers set up the practices together doesn't mean they won't both be looking to get an edge on the other. The two head coaches are both incredibly competitive – perhaps no more so than with each other – and the weekend of practice might bring back some childhood memories of competing in the backyard in Ann Arbor, Mich. Good think their dad Jack will also be in town to keep all wresting matches to a minimum.

Wide receiver Anquan Boldin finally had a proper goodbye to Baltimore fans Thursday night at M&T Bank Stadium, but now he'll spend a few days in his old stomping grounds at the Under Armour Performance Center. Boldin won't get back his old Ravens locker of three years, but he'll take the practice field with many of his former teammates. Boldin still has close ties with several Ravens and it should be a nice homecoming for the veteran receiver.

Cornerback Jimmy Smith joked that he's going to wear his Super Bowl ring out to practice this weekend to serve as a little reminder of the Ravens' 34-31 victory. Both teams have gone through some significant changes over the last two offseasons, and about half of the current rosters didn't even play in that game 18 months ago. But for the holdovers, there may be a little trash talk about the championship game when the two teams match up for full-contact drills over the weekend.

Joe Flacco and Colin Kaepernick won't be lined up against each other, but there will be plenty of eyes on both players whenever they take the field. They are considered two of the top quarterbacks in the game, but they are also two of the most consistently debated players at the position. Flacco and Kaepernick have already established themselves as franchise quarterbacks – especially with each of their big contracts – and that means the spotlight is always on them. Plus, getting Flacco and Kaepernick together will be a chance to solve the mystery of who took their Mighty Wings.

The Ravens will serve as house guests for the 49ers for the next few days, completely re-vamping the Under Armour Performance Center to accommodate the 49ers players, coaches and staff. San Francisco has a locker room and team area set up in the indoor fieldhouse, but the two teams will still share the cafeteria, showers and practice fields. The Castle will be a crowded place, and the players will have to co-exist in close quarters.

The Ravens secondary has been a point of concern during training camp because the group is thin on depth, and veteran cornerback Lardarius Webb has been sidelined with a back injury. Young corners Chykie Brown and Asa Jackson are both vying for playing time, and they'll have a chance to earn a spot with an impressive weekend against a potent passing attack headlined by Kaepernick, Boldin, Vernon Davis and Stevie Johnson. 

The Ravens spent a chunk of resources solidifying their offensive line this offseason by re-signing left tackle Eugene Monroe and trading for center Jeremy Zuttah. The group has improved during training camp, but they'll face a tough test against a talented 49ers front. The Ravens will have to block players like Justin Smith and Aldon Smith, who are both disruptive players up front. If the offensive line can hold up against the 49ers, then that's a good sign heading into the regular season.

Defensive Coordinator Dean Pees recently talked about how he wants his group to play with more confidence and swagger, getting back into the top 5. The group has taken that message to heart – specifically outside linebacker Terrell Suggs – and they are playing with an edge. Suggs is having a great camp, and he's not afraid to let people know it. Now, Suggs and the defense will look to translate that success to practice against another team.

Justin Tucker has proven himself as one of the best kickers in the NFL over the last two years, but the next three days he'll practice alongside a veteran kicker he has looked up to for years. 49ers kicker Phil Dawson – a fellow Texas alum – has been a mentor for Tucker, and now the two get a chance to work together for a few days. Tucker likes a little competition in practice, so maybe the coaches will give them a chance to test each other a bit.

The Ravens and 49ers have already been bitten by the injury bug early in training camp, as the Ravens sidelined Webb and also lost rookie defensive lineman Brent Urban (knee) and veteran cornerback Aaron Ross (Achilles) for the season. The 49ers lost defensive lineman Glen Dorsey and running back Kendall Hunter to season-ending injuries. Practicing against another team during training camp will certainly bring some increased intensity, but coaches will have to keep a close eye on the action to keep things from getting out of hand. If the two teams make it through Monday without any serious injuries, then that will be a victory.