PHILADELPHIA -- A daily review of the hot topics coming out of Philadelphia Eagles training camp:

• It isn't always easy to make sense of a fast-paced Chip Kelly practice in real time. But there were some interesting things going on Sunday afternoon. Matt Barkley, who is supposed to be competing with Mark Sanchez for the No. 2 quarterback job, may actually be competing with G.J. Kinne for the No. 3 slot. Kinne, who has been throwing the ball well, was third throughout most of Sunday's session. Last year, Kinne was cut during training camp but he finished the season on the Eagles' practice squad. Barkley has an advantage as a fourth-round pick from last year, but Kelly always says there is open competition for every job.

• Kelly's practices are broken up by intermittent teaching periods. On Sunday, those mostly turned into water breaks. Weather forecasts had called for a cooler day with rain throughout the morning and afternoon. But it was sunny and reached 90 degrees, with high humidity. The players didn't have pads on, but they were feeling the heat.

• The best evidence of the heat was the first scuffle of camp. Linebacker Trent Cole took a little shot at running back LeSean McCoy, knocking McCoy down. McCoy, who felt the defense has been a bit liberal in the amount of contact dished out, came back at Cole. The two wrestled before teammates got involved and separated them. Cole and McCoy were joking about the whole thing by the end of practice.

• Kelly confirmed Saturday that the Eagles will not tackle to the ground during practice sessions. Defensive coordinator Bill Davis said that's typical, "because of the way you expose too many people to injury on a daily basis." But it is Davis' job to teach sound tackling technique despite those limitations. "A lot of that is body placement," Davis said. "If you can continually work on putting your head in front of the ball carrier, as opposed to behind -- I think one of the biggest problems we had last year when I broke down the tackling issues was our head placement was always behind the ball carrier, leaving all arm tackles." Davis said the Eagles improved their technique during the season "and we have to build on where we left off at the end of the season."

• First-round pick Marcus Smith continues to run with the third team at left outside linebacker -- the Jack linebacker position -- behind Connor Barwin and Bryan Braman. "They come at their own pace," Davis said. "We give them every opportunity to teach and grow them. … Marcus is a very hard worker and a very intelligent guy and very athletic. So you have a bunch of characteristics you look for in all Eagles players. He cares a lot about the game. One of the biggest things that attracted us to him was that Louisville and (coach) Charlie Strong's defense is a lot like ours, and the way they used him is a lot the way we use our Jack position."