The calendar has flipped to August and training camps are in full swing. Yes, the dog days of summer have arrived. And training camps across the NFL are starting to feel like a grind. But there were a few developments on Monday and in Practice No. 9 of camp to keep things interesting.

Here are a few of them…

Sendejo back in the mixPrior to the morning walk-through, the Vikings activated safety Andrew Sendejo from the Physically Unable to Perform (PUP) list. This is a significant development not only for the defense, where Sendejo will join a crowded competition for a starting safety job next to Harrison Smith, but it's also important for the Vikings special teams because Sendejo is a multi-phase contributor there.

While Sendejo's assimilation into the defense will be something to monitor, Special Teams Coordinator Mike Priefer anticipates no delay in Sendejo finding his rhythm on that side of the ball.

"No, as long as he is physically ready, mentally, not at all," Priefer said. "Very intelligent young man, I mean he is like a coach in our meetings. He asks great questions, brings up great points."

Vikings sign free agent safetyActivating Sendejo wasn't the only roster business the Vikings conducted on Monday. They also signed veteran safety Chris Crocker and released defensive end Rakim Cox to make room for the signing. Crocker joins the Vikings after spending the last six seasons with Cincinnati, where he played under then-Bengals Defensive Coordinator and now-Vikings Head Coach Mike Zimmer. In 151 career games, Crocker has notched 554 tackles, 14.5 sacks, 60 passes defensed and 15 interceptions.

Offensive line looks good in one-on-onesThere is always a good back-and-forth between the defensive line and offensive line during their one-on-one pass rush drills. It can be a hard drill to evaluate, as well, without knowing exactly what coaches are asking of each side in that particular day's drill. Regardless, it looked as if several offensive linemen had solid showings on Monday. Right tackle Phil Loadholt kept both Anthony Barr and Everson Griffen in front of him, left guard Charlie Johnson kept Sharrif Floyd at bay, reserve Austin Wentworth worked well at left tackle and kept Scott Crichton in check, and Mike Remmers had two good reps at right tackle against Corey Wootton. 

Joseph a "good addition"Zimmer is not one to sugarcoat an answer or rely on hyperbole to get through answering a tough question. He will tell you exactly how it is. That's why Zimmer's response to a question about Linval Joseph should be considered such good news, particularly at this stage of training camp where even head coaches can start to feel the grind.

Asked how Joseph was coming along for the Vikings, Zimmer said: "Good, Linval is doing well. We're still working on his pad level. He's a big man so sometimes he gets a little bit up in his pads. I've talked to him quite a bit about when he comes off the ball, coming off with a little bit more power and a few other techniques. But I'm very pleased with how smart he is, how he wants to fit in, how important football is to him. He's been a good addition for us."

Who will backup Cullen LoefflerIt's been a while since the Vikings have had to worry about their long snapper. Cullen Loeffler has handled those duties since 2004 and he has looked good in camp this year, too. But Jared Allen was Loeffler's backup since 2008, so with Allen gone to Chicago the Vikings must find a new backup in the event Loeffler is unavailable.

Working after practice on their long snapping skills were Audie Cole, Tyler Scott, Jake Snyder and Mike Zimmer. There may be more who work their way into that group, including Michael Mauti.