EDEN PRAIRIE (AP) — The Minnesota Vikings haven’t had a player with 1,000 yards receiving since Brett Favre’s sensational season in 2009.

Stefon Diggs and Adam Thielen are on track this year to give them two.

A deep track.

Making difficult catches in tight sideline coverage or breaking open underneath the secondary, Diggs and Thielen have emerged as one of the NFL’s best wide receiver tandems. Diggs leads the league with 391 yards and Thielen is third with 358 yards, sandwiching Pittsburgh’s three-time All-Pro Antonio Brown .

“If both of those guys are singled there’s a good chance I’m probably going to throw it their way,” quarterback Sam Bradford said, “just because I do feel very confident they’re going to go out and get it.”

The Vikings have completed nine passes of 30-plus yards in four games, a pace that would double last season’s total of 18. They had 53 successful throws that covered at least 20 yards last year, and they’re already at 21 through the first quarter of the 2017 schedule.

With an offensive line contributing vastly improved pass protection and a productive running game forcing defenses to honor play-action fakes, the Vikings have so far displayed a dynamic, creative, versatile attack under offensive coordinator Pat Shurmur in his first full season at the play-calling helm.

“When we have an opportunity, we’ve got to make the most of them,” Thielen said. “Because we don’t know when we’re going to have those shots and when they’re going to come up.”

Bradford, who has missed the last three games because of a left knee injury, set the NFL record for completion percentage last year out of necessity behind a struggling offensive line. The running attack was nonexistent, too. Going deep was hardly possible, even if Diggs and Thielen had the ability to turn such play calls into momentum-changing completions.

“Pat’s just drawing it up, what he sees and what he likes. He’s letting Adam do some great things. Adam’s got some great hands. He runs some great routes,” Diggs said. “So I just feel like it happened organically.”

Don’t get too comfortable, Cris Carter and Randy Moss. Diggs and Thielen have begun to push their way toward the top of some of the lists of the franchise’s all-time leaders.

Sidney Rice was the last 1,000-yard receiver in purple, in 2009. Before that, Moss in 2003 completed a streak of 11 straight seasons with at least one. Seven of those featured two: Carter and Jake Reed each year from 1994-97, and Carter and Moss from 1998-2000.

The primary difference with Diggs and Thielen — both a bit undersized by NFL standards — is that they had to work harder to reach this status. Diggs was a fifth-round draft pick out of Maryland in 2015 and a healthy scratch the first three games of his career. Thielen famously signed out of an undrafted tryout camp in 2013, spent a season on the practice squad and another couple of years primarily on special teams until his breakout in 2016.

But they’re both exceptional route runners, with an ability to line up inside or outside and make a shallow cross or a deep post work whenever the situation calls for it. With Brown as an example, the league has seen more and more versatile wide receivers who can confuse and confound defenses by moving all over the formation rather than being limited to either the outside or the slot.

“When a quarterback is in trouble, they’ll come down with the ball,” said wide receiver Michael Floyd, who’s coming off a four-game suspension and set to join the Vikings as another dangerous down-field option when they play at Chicago on Monday. “That’s expected in our room.”

Diggs broke out ahead of Thielen, but he said he’s looked up to his teammate as an example of precise route-runner. Shurmur likened Thielen to an outfielder in baseball for his ability to judge the ball and adjust to it in flight for a catch even if he hasn’t separated himself from the defender. Both Diggs and Thielen have a keen sense for how to bend a route away from a cornerback to make an interception impossible and a difficult reception look routine. Diggs in particular has a reputation among the Vikings defense for being relentlessly competitive.

“He won’t ever stop. He catches a ball in practice, he’ll run all the way to the end zone,” cornerback Xavier Rhodes said.

The key for the Vikings will now be to keep up this deep passing game with the loss of running back Dalvin Cook , whose early success was setting up those play-action fakes.

“But also, it’s part of what they do now,” Detroit coach Jim Caldwell said last week, before his team beat the Vikings 14-7. “Before they had been getting the ball out fairly quickly, intermediate passes and those kinds of things, and occasionally down the field. Well now they’re attacking down the field with that real strong running game, so that’s what’s made the difference. Those guys are running really good routes, catching the ball well.”