Courtney Lawes believes he has been experiencing a 'dip in form' during recent weeks.
But the England star has vowed to get back to his best in the months to come.
Lawes was a stand-out player for Saints during 2017 and he also starred for England and the British & Irish Lions.
He recently became a father again as his partner gave birth to twins.
Lawes celebrated by helping Saints, who had lost their past seven league games, to secure a crucial 22-19 victory against Gloucester at Franklin's Gardens last Saturday.
And he said: "I've had a bit of a dip in form in the past few weeks.
"There's a lot going on in my life, which makes a difference, but I'm working hard and I want to push through it.
"I know I will come through the other side, just as Saints have, and I will get back on that horse."
Lawes looks likely to play a key role for England once again when their Six Nations campaign starts next month.
And the lock said: "I want to put my hand up for that squad.
"I want to go out there and play my best.
"I'll always work as hard as I can.
"If I keep on trying to improve, eventually that form will return."
On Saints' recent form, Lawes said: "It's been tough.
"We've gone through a bad patch but we've got that win and hopefully we can really push on from here.
"It's not going to be easy, we need to keep working hard and look to improve every game.
"It felt completely different out there last weekend to previous weeks.
"Even when Gloucester scored, we stayed positive, kept the next job mentality and we came back well.
"Our ball retention's really poor at the minute but if we can keep hold of that ball, we're going to give sides a good run."