Humphreys, who starts alongside fellow Irishman Frank Murphy at half-back, hopes that he can lead Tigers to a valuable victory at Welford Road.
"The main priority is winning," says the 24-year-old. "Obviously I want to do well from an individual perspective, but the most important thing is that the team comes away with a win.
"Last year, London Irish were one of the top sides during this stage of the season, so we know they will be tough to beat. Hopefully we can play well as a side and then we'll see how it goes for the rest of the season."
Humphreys has been one of the stars of Tigers' successful Guinness A League campaigns and will be hoping to replicate that consistency at first-team level.
Helping him make the transition to Premiership rugby will be former Munster No.9 Murphy, his half-back partner throughout the early part of the season. It is a partnership that has seen Tigers Development XV produce an exciting brand of rugby and is one that will suit both men tomorrow.
"Having Frank at nine is a big plus. We've been playing together all season so we know each other's games pretty well. We get on well and we enjoy playing alongside each other, so that's a good thing for both of us," Humphreys says. "I'm definitely feeling really comfortable knowing that Frank's starting at scrum-half and hopefully we can perform well."
Although Premiership rugby is not an entirely new experience for the ex-Belfast Harlequin, this will be a first league start at his home ground for Humphreys.
"All the first-team games I played last year were away from home, so this is the first time I'll have started a senior match at Welford Road. I've played in front of big crowds here in the Guinness A League, but this will be something different and I can't wait to get started. I'm determined to take my chance."
The Guinness A League's current top points-scorer has returned from a short loan spell at National One side Leeds Tykes, an experience which he believes will benefit his push for first-team inclusion here at Tigers.
"I enjoyed my time at Leeds and I have no regrets about going there. I learnt a lot about myself and about my game, so that was a positive thing. I played three-and-a-half games during the loan and gained a lot from that game-time.
"Although it can be frustrating not being involved with Tigers, I knew the situation when I came to Leicester and it's something I accept as part and parcel of the competitiveness of the squad. Goodey and Burkey have massive amounts of experience and that's something I can learn from. It's the same with Pat, who played 10 and 12 to a very high level. Hopefully now I've been given my chance I can use that to push on."