(Photo credit: John E. Sokolowski-Imagn Images)

Veteran quarterback Trevor Harris returns to action and the Saskatchewan Roughriders aim to remain unbeaten when they host the Calgary Stampeders on Friday night in Regina.

Harris sustained a concussion in a Week 3 victory over the Toronto Argonauts. The Roughriders picked up a win behind backup Jake Maier and then had a bye last week.

Saskatchewan (4-0) leads the West Division while Calgary (3-1) is tied for second with the Winnipeg Blue Bombers.

'We're excited about the challenge,' Harris told reporters of facing the Stampeders. 'They bring a great challenge to us, but we think we bring a great challenge to them as well.'

Harris, 39, knew something wasn't right during the 39-32 win over the Argos on June 20 but didn't tell coaches or trainers until after the contest.

'I was a little bit fuzzy, but I felt good enough to execute,' Harris said. 'I don't condone what I did in terms of staying in there, but it's no fault of the team, no fault of the docs. I didn't report anything.'

Harris is completing 72.5 percent of his passes for 806 yards, five touchdowns and three interceptions this season.

Saskatchewan's AJ Ouellette leads the CFL with 347 rushing yards. He's averaging 6.2 yards per carry and has rushed for three scores.

Calgary also has a thriving runner in Dedrick Mills, who is second with 311 yards and has rushed for a league-high five touchdowns.

Stampeders quarterback Vernon Adams Jr. threw his first two touchdown passes of the season in last week's 37-16 rout of visiting Winnipeg. He has passed for 1,025 yards and been intercepted three times.

Adams is aware he needs to be in top form with Saskatchewan leading the CFL in rushing defense at 66.5 yards per game.

'This is a battle for first place so it means a lot,' Adams said during media availability. 'They're playing at home so they're going to bring their best game.'

Defensive back Damon Webb (30 yards) and linebacker Derrick Moncrief (70) returned interceptions for touchdowns to help spark Calgary against Winnipeg.

Overall, Calgary has three interception returns for scores. Adrian Greene also turned the trick against Toronto in Week 2.

'We've been keeping our heads low, going to work every day, and the results are showing right now,' Webb told reporters.

Calgary has thrived on the road in the series, winning the past five visits to Regina and 10 of the last 11. The Roughriders' win during the stretch came in 2018.

--Field Level Media