Neil Harris insists he will bolster his Millwall squad in the summer transfer window, ahead of the club’s return to the Championship.

The Lions beat Bradford 1-0 at Wembley in the League One play-off final to mark their return to the second tier of English football.

Millwall, who were beaten in last year’s play-off final, finished the season in sixth and Harris is determined to create a competitive squad at The Den.

“The Championship is a fantastic league, it’s moved on massively in the last 10 years,” Harris said after Millwall’s 1-0 win over Stuart McCall’s Bantams.

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“The amount of money in that division now is phenomenal.

“We’ve got a really good core group and the spirit is enormous, but there’s no doubt we’ll have to add a few new faces.

“We’ve got some players with Championship experience and a few younger players.

“We’ll take a day or two to consider our options but it's clear we’ll make sure we’re a competitive side next year.”