Having claimed three consecutive SPL titles under predecessor Neil Lennon, in addition to producing one of the most Champions League nights in recent European football history, new Celtic manager Ronny Deila has rather large shoes to fill at Parkhead.

The Norwegian gaffer, formerly of Stromgodset, has his first challenge to face this summer, with rumours that highly-rated Bhoys duo Fraser Forster and Virgil van Dijk could soon be on the way to the Premier League.

With those potential departures in mind, in addition to a number of gaps in the Celtic squad that require addressing - Lennon had billed the summer window to include five or six major signings - we at Football Fancast have conjured up a list of FIVE players that would complete Deila's Celtic squad, allowing the Scottish Champions to effectively defend their title next season.

[ffc-gallery]CLICK ON RHYS WILLIAMS TO REVEAL

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DAVID MARSHALL

With Frasier Forster expected to depart Parkhead this summer and injury-stricken bosman signing Craig Gordon still very much an unknown quantity, acquiring the services of a talented goalkeeper is a must for Celtic.

One option open to the Bhoys is Cardiff City's David Marshall, a former understudy 'keeper at Parkhead, who made more saves than any Premier League goalie last season, as detailed below...

Had the Scotland international not enjoyed such a rich vein of form, the Bluebirds relegation campaign could have been a lot more embarrassing. Here he is keeping Tottenham at bay in one of his many Man of the Match displays last term...

And with the Welsh outfit plummeting back into the Championship, the 29 year-old is expected to move onto bigger and better things this summer.

His £5million-£8million valuation, depending on sources, should be just within Celtic's financial reach. But recent speculation suggests he's already being eyed by Southampton:

Stevie May

If Celtic are to maintain their stranglehold on the SPL, acquiring Scottish football's hottest up-and-coming talents is a necessity. In this regard, I refer to St. Johnstone sensation Stevie May.

The ponytailed assassin has been in lethal form over the last three campaigns, bagging 72 goals in his last 93 competitive appearances, including potent loan spells with Alloa Athletic and Hamilton Academical. Here's some of the 21 year-old's highlights from last term...

And as you can see below, his individual contribution to the Saints' cause - netting 27 times in all competitions - was amongst the best in the Scottish top flight last season...

May also netted this winner in the Scottish Cup final...

The Scotland U21 is a fine talent, and Celtic could certainly do with a dependable goalscorer with January signing Leigh Griffiths' future remaining unclear.

Furthermore, his contract is set to expire next summer, making the current window the ideal opportunity to buy, but the Daily Mail believe the striker could soon be on his way to QPR.

ISHMAEL MILLER

Another striking addition for the Scottish champions to consider is former Nottingham Forest front man Ishmael Miller, now a free agent.

The 27 year-old is a rather mercurial figure - his impressive loan spell at Yeovil last season was cut short after falling out with manager Gary Johnson, and it's hardly the first time he's been involved in controversial off-pitch incidents.

But previously, Miller had been in lethal form for the Glovers, as detailed below...

In case you need further convincing, some nutbag has created a twelve-minute compilation of the former Manchester City trainee's career highlights...

Measuring in at 6 foot 3, boasting brute athleticism and available on a free transfer, the English forward could prove to be an astute addition for Celtic.

According to Miller however, there's global interest in his services this summer...

RHYS WILLIAMS

Neil Lennon was keen to add a new centre-back to the mix in January, with his man in mind reportedly being Middlesbrough's Rhys Williams.

Well, the issue of added quality at centre-half still persists at Parkhead, especially amid rumours Virgil van Dijk could soon be heading for the exit door:

Capable of playing at centre-back, right-back or even in midfield, the Aussie international would be a more than acceptable replacement. He was in good form for Boro last season too, as detailed below...

Here's the highlights from the 25 year-old's 2011/12 campaign, where Williams won the Player of the Year award at the Riverside Stadium...

It's believed he could be available for around £1.5million, but after suffering an Achilles injury at the end of last season, it remains to be seen if Ronny Deila will be prepared to maintain his predecessor's interest in the defender.

MIKKEL DISKERUD

Hot off the press this morning, the Bhoys are reportedly eying a deal for 20-cap USA international Mikkel Diskerud.

The 23 year-old failed to feature for Team USA at the World Cup, but comes with a strong reputation from his two campaigns spent with Rosenborg, claiming four goals in 43 league appearances and last term helping his current club reach the Norwegian Cup final.

Here's the highlights from Diskerud's time with The Troll Kids and former club Staebek:

And with the Norwegian side reportedly keen to trim the fat, it's believed a Parkhead move could be just around the corner. Rosenborg will certainly be keen to cash-in before the midfielder's contract expires at the turn of 2015.

But rumoured interest from Bundesliga side Werder Bremen could become a stumbling block: