The Scotsman has put in impressive performances against Coventry, Fleetwood and Sunderland over the past few weeks.
But the full-back was left out of the Saddlers starting XI for the clashes against Wycombe and Burton around a month ago.
And the 25-year-old admits he found it tough being left on the sidelines.
“It’s always difficult because you’re a professional footballer and you want to play games,” Devlin said.
“You’re training all week and if you don’t play on the Saturday, it feels like you’re not really doing your job – it’s only half a job you’re doing.
“It was difficult but I experienced last season and that’s made me more mature.
“I’m just delighted I’ve got myself back in. I’ve done okay but I know I can do better.
“For me, it’s about getting a level of consistency that makes it almost impossible for the gaffer to leave me out.
“That’s what I’m personally aiming for.”
Devlin is enjoying his second season in League One after being snapped up from Ayr United at the beginning of the 2017/18 campaign.
And he feels he has improved as a defender over the past 12-months.
“I’d be the first to admit that I didn’t think I had a great season last year,” Devlin continued.
“I do feel my performances this year have been better, and the team performances have been as well, which has helped.
“I feel defensively I’ve looked more solid.
“I was probably a bit vulnerable at times last year when I wasn’t playing well and lacking confidence.
“I feel I’ve got that back now and I’m putting in better performances.”
Walsall take on league leaders Portsmouth at Fratton Park tonight.
But while the hosts will be favourites, Devlin says the team enjoys being labelled underdogs.
“The more people write you off, the more it should fire you up and make you want to do well,” he added.
“We’ll go into the game as underdogs but we all know in our dressing room that if our big players turn up, we’ll have every chance of winning the game.”