McDonald, a former second-round pick, has been a disappointment in his first three NFL seasons. Frequent lapses in concentration have led to drops, including five in 2015. Even in his best NFL season last year, McDonald still posted a modest 30 catches for 326 yards and three touchdowns.
"It's a mindset," McDonald said. "You can control your attitude. I've heard that before but for some reason, when he said it, we have come in here every single day with a positive attitude with the mindset of working and focusing on what little detail can I get and take hold of that day and accomplish?
"My word is consistency. Just build on it throughout training camp and we'll see what happens when the season starts."
If the first half of the preseason is a harbinger of things to come, McDonald could be in for a long-anticipated breakthrough season. McDonald has started both preseason games and posted five catches for 92 yards and a touchdown, leading the team in each of those categories. It hasn't been flawless -- he didn't come down with a catchable ball against Denver last week -- but it's at least been encouraging that McDonald could take hold of the starting job and produce beyond his previous seasons.
"I think Vance has done a good job," offensive coordinator Curtis Modkins said. "Vance has made some plays for us and hopefully he'll continue."
For that to continue, McDonald will need to string together practices and games in which he proves a reliable target. To this point in the preseason, 49ers quarterbacks have regularly looked for the tight ends. And tight ends are common targets in coach Chip Kelly's offense. In Kelly's time in Philadelphia, tight ends such as Zach Ertz and Brent Celek have posted big numbers. Ertz had 75 catches for 853 yards and a pair of touchdowns in 2015.
The success of Kelly's previous tight ends isn't lost on McDonald, who says he's enjoying playing football again in part because of the birth of his son. But in a season that looks pivotal for the trajectory of McDonald's career, he seems more relaxed than ever. In fact, he says the pressure is off even as he enters a contract year.
"Thinking about it in the offseason, it's just comes down to a little focus thing," McDonald said. "We’ve been talking about that the last couple of years but really, on top of the pressure being off of it, just coming in, letting loose and focusing on the tiny little details of watching the nose of the football, eliminating all the other stress and pressure."
If McDonald can do that during the season, he'll have an opportunity to stick as the 49ers' starting tight end.