Millwall 3-3 Real Sociedad: The warmdown after final friendly for Lions
LONDON, ENGLAND - JULY 27: Aritz Elustondo of Real Sociedad battles for possession with Jiri Skalak of Millwall during the Pre-Season Friendly between Millwall and Real Sociedad at The Den on July 27, 2019 in London, England. (Photo by Harriet Lander/Getty Images)

Millwall have had a busy summer - but still, want at least two more signings. Yesterday, Neil Harris' side played their usual final friendly against foreign opposition at The Den on Saturday, drawing 3-3 with a Real Sociedad side featuring the likes of Adnan Januzaj and Asier Illarrimendi.

1. Lions must cut out defensive lapses

All three of Sociedad's goals came from Millwall mistakes. Firstly, the defence was cut apart by one through ball, allowing Alexander Isak to finish past Frank Fielding from close range.

Following that warning, the hosts' midfield was nowhere to be seen as Zururuza was given space to fire off a long-range effort, beating Fielding all ends up as it met the corner of the net. Since their return to the second tier, the Lions have conceded plenty of long-range efforts but appear to have not yet heeded those numerous warnings.

The third was a little luckier as there was a deflection or two, though Millwall's team as a whole should've dealt with the move more quickly and efficiently. 

2. Connor Mahoney will be key

It may have been his first outing in SE16, but if the former Bournemouth man continues to perform as he did against the Spaniards, he will prove to be a fan favourite with the Millwall faithful.

Mahoney's delivery is excellent, both from wide areas and dead balls. With Matt Smith and Jake Cooper - who scored seven times last season from centre back - amongst those to aim for, his service should prove extremely useful and he could end up with a number of assists. He has already assisted Cooper once in pre-season at Priestfield in a 2-1 win over Gillingham, with the former Reading man heading in Mahoney's corner.

His ability to play on either wing allows Harris to play any combination of his wingers - Jiri Skalak, Jed Wallace, Shane Ferguson and Mahoney - which will allow the Lions to have more tactical flexibility than last season.

Yesterday gave Mahoney a chance to showcase his quality and he did just that, scoring an excellent goal as well as delivering a number of superb crosses. He is confident in both the way he speaks and his style of play, skinning his full-back yesterday before finishing with his left foot into the top corner, giving the goalkeeper absolutely no chance as he cut inside from the left-wing following Mahlon Romeo's knockdown.

3. Jed Wallace is no longer a guaranteed starter

Millwall's fortunes last season rested far too heavily on the form of Jed Wallace - who played through plenty of knocks and niggles to help the Lions limp over the line to Championship safety.

Wallace wasn't in the best of form as a result and has endured a rather average pre-season, seeming reluctant to take on his man yesterday - usually one of his main strengths.

However, his crossing did seem better than usual, though there is still work to be done. Having begun his career at Fratton Park as a number ten, crossing had not been a major part of Wallace's game - but Neil Harris favours the use of a 4-4-2, meaning the former Wolves man has to play as a wide man.

With Mahoney, Skalak and Ferguson all being excellent crossers of the ball and the Lions' strikers - particularly Smith and Jon Dadi Bodvarsson - relying on good service into the penalty area, Wallace may well lose his place at times this season, a warning that Harris gave to the winger in his post-match press conference yesterday, telling the media: "What it will do is make Jed Wallace a better player, where he lacks in end product at times he’ll have to improve. He’ll know who’s in the box and what deliveries he’s got to put in."

4. Ben Thompson is a guaranteed starter - but who will partner him in midfield?

Put simply, academy graduate Ben Thompson has to be one of the first names on the team sheet. He was crucial after returning from a loan spell at Portsmouth in January last season, and has performed well in pre-season thus far, especially yesterday.

His energy and ability to go from box-to-box is key in a system with just two central midfielders, countering the fact that most teams will have an extra man in that area to an extent. Having now added goals to his game - of all sorts - he will surely start when fit, with Harris also believing that he will be a captain of Millwall in the future.

Yesterday's goal was a superb strike from just outside the box, cutting in from the left slightly to cut across the ball and fire it into the top corner.

However, his midfield partner - the Irishman Shaun Williams - was less impressive. Williams has now missed his last two penalties for Millwall, with both having been very tame efforts - against Bristol City and then Sociedad. 

Williams doesn't match Thompson's energy and with many expecting him to be the deeper midfielder of the two, he was beaten far too easily with Sociedad's midfielders dribbling past him with little trouble. Sometimes, the way Millwall play doesn't suit Williams' best quality - undoubtedly his passing - but Ryan Leonard isn't a fans' favourite either.

After signing for a record fee, Leonard struggled at times in 2018/19, though fans will be hopeful he can improve this campaign with a full pre-season at Calmont Road under his belt. Leonard's energy also suits a two-man midfield, though he is sometimes technically limited and thus gives the ball away cheaply too often, leaving fans questioning whether he can play the deeper role with Thompson getting forward to add goals from midfield.

Jayson Molumby joined on loan from Brighton last week but is not yet match fit, so Harris will have to wait to see if he is the suitable partner - which I suspect he will be. A hot prospect, the Irish midfielder can take on any role in midfield and is a superb passer of the ball, a quality which the Lions will perhaps hope to make more use of from his likely screening role.

Given Thompson's initial standing as a defensive midfielder, a partnership between him and Molumby would allow for either to get forward and allow them to switch roles, providing opponents with a different problem altogether.

5. More pace wouldn't go amiss

You'd struggle to name a player in the Millwall squad who would be described as 'extremely quick'. Mahlon Romeo, Jed Wallace and Connor Mahoney are no slouches, much like a number of other players - but there is no one with that ability to gain three or four yards on someone in a few seconds.

That pace, combined with quality would add a different dimension to Millwall's attack - assuming it would be a winger/forward if someone were to sign. Jamal Lowe was a target earlier in the window, but it seems unlikely that the Lions will go back in for the Portsmouth man having signed Mahoney.