Neil Harris could build on an impressive first season back in the Championship with these free agents.

It will be hard for Millwall to replicate the run they have been on this season because they have gone from League One play-off winners to seventh place in the Championship, with an outside chance of finishing in the play-offs.

Teams will be more prepared for them next season as well as not underestimating them, and the 17-game unbeaten run they went on would be hard for most Championship teams to repeat due to the sheer consistency it requires.

However, that is what Neil Harris is tasked with. Here are six players they could bring in as free agents which suits their financial situation...

Bjelland's contract at Brentford is coming to an end after three seasons at the club. He has been a reliable performer for the club in his time there, but he wants to move on. This would be somewhat of a sideways step for him based on league positions as well as a shift in styles, but it could be a good fit.

Millwall do have a strong centre-back pairing already, but Bjelland could provide competition for them and bringing him in for free is a relatively risk-free move even if it fails.

Onuoha is another centre-back option that could be brought in to bolster the back line. He possesses plenty of experience and he is used to the direct style of play which Millwall utilise.

Squad depth is a key area for Millwall to develop because Harris has created a strong settled first XI, but they need more cover for when players are injured or pick up suspensions. There is also the factor that bigger clubs may try and take some of their top performers away, so Onuoha would be a good acquisition even if he was just used for rotation.

It might be surprising to hear that Gunnarsson's contract runs out in the summer even though he has been a strong performer for Cardiff in their promotion push. Neil Warnock wants him to stay longer, but negotiations are at a standstill so Millwall can take advantage of the situation.

He would be a good option to bring in because of his positioning, anticipation and mentality which ensures stability in the central areas and helps make the team hard to break down. Gunnarsson would certainly provide competition to Shaun Williams for his spot, and is likely to be an upgrade on him.

Wallace has been an important player in Wednesday's promotion pushes over the past few seasons, but he is past his peak and it is starting to show.

However, he could be used in a bit-part role on a short contract by Millwall because he is willing to work hard defensively and is dangerous from set pieces as well as being adept at cutting back on to his left foot and putting in precise inswinging crosses.

Hoilett is another winger who is a free agent in the summer, which is more of a surprise considering how well he has performed for Cardiff. He is valued at £3.15 million by Transfermarkt, so he would be a smart acquisition.

Nine goals and 11 assists in 3640 minutes is a great return which shows his danger in the final third with key passes being his area of expertise, and his pace means he is a dangerous counter-attacking threat. He would be the ideal player for Harris to bring in.

Nuhiu is a talented target man and has found form in recent months, but hasn't been rewarded with a new contract. He has eight goals and five assists in 1271 league minutes, so he is close to averaging a contribution every 90 minutes.

The Kosovan international would work well in Millwall's system with direct play to him as an outlet and another striker playing off him. He has a strong aerial threat and the Lions have all the tools to utilise that effectively.