SANTA CLARA, Calif. (AP) It took less than 30 minutes into the San Francisco 49ers' first training camp practice for the Levi's Stadium sod to come up in pieces, also only a couple of hours after the venue hosted a high school all-star game.
The Niners kicked off their first training camp under new coach Jim Tomsula on Saturday night with hundreds of fans in the stands, and he could be seen stomping down a divot with his heel moments after watching wide receiver Bruce Ellington run a route a few yards away.
Tomsula said after practice the grounds crew was ''going to roll it, they're going to work it all night,'' and he expected to hold Sunday afternoon's practice in Levi's Stadium as planned though moving to another practice field remained an option. The team is scheduled to hold its first eight practices in the stadium.
''We're not going to put them at risk,'' Tomsula said. ''Just talking about the grass right away, we probably need to think how we do an individual period. Individual chewed us up right here with the wide receivers and the DBs down there along the edges. The middle of the field's good, so the team period I wasn't concerned about at all. ... We're not going to come out here if it's not safe.''
He cut a minute or two out of individual work.
Longtime stadium operations chief Jim Mercurio has said the sod will be replaced on an as-needed basis and perhaps as many as six or seven times, and the team said Saturday it is next scheduled for mid-month following a pair of concerts by Taylor Swift on Aug. 14-15.
The year-old, $1.3 billion stadium is set to host the Super Bowl in just more than six months. The NFL is expected to bring in its own field and is already in regular communication with the 49ers' stadium operations staff.
''The number of large-scale events has kind of put us into a planning stage where we have to decide and determine how we're going to attack it,'' Mercurio, the 49ers' vice president of stadium operations and security, said recently. ''Sometimes you don't know if it's going to be a full replacement, we don't know if it's going to be a partial replacement.''
In one small section between the 25- and 30-yard lines on the North side of the stadium Saturday, there were some 30 visible small chunks that had loosened.
Levi's hosted Barcelona and Manchester United in the International Champions Cup on July 25. Afterward, Barcelona coach Luis Enrique said, ''The field was dry and I think that hurt both teams as well.''
The field receives regular direct sunlight and it can become very hot inside the venue.
The sod was a problem last season as well, when former coach Jim Harbaugh even pulled his players off the slippery Levi's Stadium grass early one day in August when it began to come up, they had trouble keeping their footing and he determined it a risk for injury.
Mercurio said that the team might consider synthetic turf for its surface after the Super Bowl.
Last August, the 49ers re-sodded the field from goal line to goal line and sideline to sideline with longer grass after the initial sod laid in April 2014 failed to hold up at least well into the regular season as was expected. It was then sodded for a third time in four months before the start of the regular season in an effort to find the right grass and soil combination that would stay rooted.
The much-scrutinized field again featured visible chunks of loose sod for the regular-season debut at Levi's Stadium on Sept. 14, a 28-20 loss to the Bears in prime time.
''There's a test that the NFL requires all stadiums, all fields, to go through to make sure it measures the density of a field, how soft it is, how hard it is,'' Mercurio said. ''And there are certain requirements that you have to stay within whether you're turf or whether you're sod, so what we'll do is we'll use that same measuring technique or something similar to make sure if there's ever a transition period - it's one of the concerns of us, the owners, (GM Trent) Baalke - to make sure safety is primary, No. 1. So that's how we'll measure that.''
The 49ers reached an agreement with West Coast Turf to have its own designated section of sod so it is always ready when the franchise might need to change the grass. San Francisco also installed some synthetic turf this offseason around the outer, high-traffic section of the field that has helped with conserving water in drought-starved California.
''I'm hoping it turns out to be a smart move, so far it's been its weight in gold,'' Mercurio said.
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