Stanford head coach David Shaw feels a lot more confident in Davis Mills’ ability to lead the Cardinal offense against No. 15 Washington on Saturday than he does about the potential for starting quarterback K.J. Costello to return.

In his second career start against Oregon State on Saturday, Mills looked considerably more comfortable and poised in the pocket than he had three weeks earlier when he subbed for Costello the first time.

Mills passed for 245 yards and three touchdowns, completed 72% of his throws, then caught a touchdown pass from tight end Colby Parkinson to help Stanford (2-3, 1-2 Pac-12) end a three-game losing streak.

That growth, Shaw said, was both comforting and expected, considering Mills’ limited playing time. He played only one series in 2018 before a season-ending knee injury, and has been in and out of the lineup this season while Costello has dealt with head and thumb injuries.

“The more you play, the more comfortable you are, the more experience you have,” Shaw said Tuesday. “To have talent without experience, you’re going to get uneven play. There are some throws (Mills) missed at USC (on Sept. 7) that he didn’t miss this past weekend. It wasn’t anxiety or nerves. It’s just a little lack of experience and having that feel. There’s nothing like having the feel of a game and growing in that and getting experience from that.”

Costello had been Stanford’s starter since 2017 but injured the thumb on his throwing hand when he hit it on another player’s helmet while following through on a pass against Oregon on Sept. 21.

Costello is hoping to do some throwing after being held out of practice last week, although Shaw didn’t sound optimistic.

“K.J. is still listed somewhere between questionable and doubtful,” Shaw said. “He’s going to throw some today and see how that goes. I have no doubts about his passion. I have no doubts about his ability. This is just health.”

The Cardinal face an uphill challenge against the Huskies no matter who starts at quarterback.

Washington (4-1, 1-1) historically has been tough to throw against and that’s certainly the case this season. The Huskies are giving up 203 yards a game in the air. They allowed only three completions longer than 10 yards in Saturday’s 28-14 win over USC.

“They are nonstop,” Shaw said. “We can’t afford to have lapses against a good football team like this. You start slow against Washington, you’ll be down 21-0. They’ve proven that.”

On the flip side, Stanford has won 10 of the past 14 games against the Huskies.

Then there’s this tidbit: Mills has passed for more yards (482) and touchdowns (four) in his first two starts than any Stanford quarterback since 2003. That includes former NFL quarterbacks Andrew Luck and Kevin Hogan.

“We’ve never felt like we had to do less with Davis,” Shaw said. “He’s very smart, very bright. His movement on the touchdown pass, outside the pocket, being able to avoid a defender and still being able to put the ball in the back corner of the end zone … those things are really what help him take the next step and not necessarily us putting more of the offense on his shoulders. Just him being able to relax and make plays.

“Didn’t play perfectly. Has multiple things that he’s gotta get better, but for the most part, he took the next step and most likely, he’s going to play again this week and hopefully, he takes another step.”

Michael Wagaman is a freelance writer.