His patience has been tested with the suspension of his star running back, myriad kicking issues, near-annual changes at quarterback and offensive coordinator — not to mention his own vision problems in 2016. But in Mike Zimmer’s 4 ½ seasons as the Vikings’ head coach, perhaps one of the few irritants he hasn’t faced is a spate of turnovers.

A year ago, the Vikings’ 14 turnovers were the third fewest in the NFL. Case Keenum threw only seven interceptions, Teddy Bridgewater threw one and the team lost a total of six fumbles.

In 2016, the Vikings’ 16 turnovers were the seventh fewest in the league, with just five coming on Sam Bradford interceptions. Seventeen turnovers in 2015, including nine Bridgewater interceptions, put them fourth best in the NFL. Even in 2014, when Bridgewater threw 12 interceptions as a rookie, the Vikings were sixth best in the league with 20 turnovers, having lost just two fumbles all season.

That’s all changed this year.

In 2018, the Vikings are tied with the Eagles — the team they faced in the NFC Championship Game last year — for 26th in the league with 16 turnovers, already having surpassed their total from all of 2017 and matched their 2016 total.

They committed three in Sunday night’s 25-20 loss to the Bears, with Dalvin Cook fumbling in the red zone and Kirk Cousins throwing two interceptions. The first was a byproduct of miscommunication with Kyle Rudolph at the end of the first half, and the second was returned for a critical touchdown in the fourth quarter.

“It’s been frustrating at times,” Zimmer said. “Like the Saints game, we’re getting down there, we’re getting ready to score and Adam [Thielen] fumbles the ball, and he’s pretty good with it. I guess stuff happens sometimes.”

Their nine lost fumbles are tied with the Eagles and Packers for the second most in the NFL, and Cousins’ seven interceptions are tied with Keenum’s total from 2017, though with Cousins throwing the ball more often than any quarterback but Ben Roethlisberger this season, his interception rate is only slightly higher than Keenum’s was in 2017 (1.7 percent to 1.5 percent) and is still the seventh lowest in the league this season.

Cousins has lost more fumbles (six) than any player in the league. Combined with his seven interceptions, he is tied for second in the league with 13 turnovers, behind only the Jets’ Sam Darnold with 15.

Zimmer said Monday he has talked with the quarterback about his turnover issues, and then added, “I really don’t think he’s panicking.

“I think there’s times where he wants to get the ball down the field, so he’ll wait for guys to get open, instead of maybe taking the sure thing. But other than the turnovers, I have a hard time faulting him.

“This kid is tough. He plays outstanding. He works his rear end off. He’s a great team guy. And quite honestly, not all of them are [his fault]. Guys are in the wrong spot sometimes, too. And that’s not just our team; that’s every team.”

The Vikings opted to sign Cousins — whose 47 turnovers tied him with Cam Newton for the fifth most in the NFL from 2015 to ’17 — over the three quarterbacks (Bridgewater, Bradford and Keenum) who had produced low-turnover seasons in their offense. They drafted Cook knowing he had fumbled 13 times in college; on Monday, Zimmer referenced a comparison he’d made after the Vikings picked Cook, about how former Giants running back Tiki Barber had curbed his fumbling issues later in his career.

Turnovers were on the résumé of both players, along with the attributes that drew the Vikings to them. As with any player, the act of accentuating strengths and buffing out weaknesses might be more art than science.

“It’s all part of the process,” Zimmer said. “If a guy’s a fumbler, that’s part of it. But, you know, guys can change. Tiki Barber had a huge fumbling problem before fixing it. It’s just a process for some guys.”

The process of eliminating their turnovers, though, is no less crucial for the Vikings.

In Zimmer’s time as coach, the Vikings are 30-6 when winning the turnover battle (as a sign in the team’s quarterback room reminds players). They are only 9-17-1 when losing it — counting a victory over the Lions on Nov. 4 — and 6-8 when they are tied with their opponent in turnovers, as they were with the Bears on Sunday night.

The Vikings, who have increased their number of takeaways this season, still have a plus-1 turnover margin for the season, and they would like to keep that number above zero; of the 48 teams to make the playoffs in Zimmer’s first four years as coach, only eight have done so with a negative turnover margin.

“I think that’s where Coach Zimmer certainly ought to be disappointed with us, when he’s coaching us and telling us what we’ve got to do, and those keys to victory aren’t getting done,” Cousins said Sunday night. “So that’s where we have to make sure that next week, when we get back at it, that whatever the keys are, they’re executed.”