Chris Sutton expects Rangers' January recruits to fit seamlessly into Steven Gerrard's line-up – but he is not so sure of Brendan Rodgers' "risky" new signings.

While their Old Firm rivals have gone down the tried-and-trusted route by securing deals for Jermain Defoe and Steven Davis, the Celtic boss has stuck by his policy of snapping up rough diamonds to be polished up.

The Hoops have splashed out a reported £2million to lure 21-year-old Vakoun Issouf Bayo from Slovakian side Dunajska Streda while Oliver Burke and Timothy Weah have also arrived on loan.

But outspoken TV and radio pundit Sutton reckons Rodgers is taking "a punt" on a young trio yet to prove they can cut it at the highest level.

And with Rangers ready to go out all guns blazing in the second half of the season following last month's Old Firm victory as they bid to halt Celtic's charge for eight league championships in a row, the former Parkhead striker has warned Rodgers this is a call he cannot afford to get wrong.

Sutton told Press Association Sport at the launch of Premier Sports' Scottish Cup coverage: "The jury's still out. Timothy Weah has good potential but he's not proven. It's the same with Bayo.

"Burke's also got a point to prove. He's had a couple of big-money moves but hasn't realised his potential.

"Rangers have gone down the route of buying players that some may say are past their sell-by date – I don't – while Celtic have gone the other way bringing guys who are raw.

"Defoe has shown all his career he's a top finisher and Davis can give them the creativity they have missed.

"You tend to think Davis will come in pretty seamlessly. Defoe probably the same, as we know he can finish. They may have to get a bit of rustiness out of their legs as they haven't played much recently.

"These are players who have had top careers because they have looked after themselves. I expect them to make an impact.

"However, Celtic have taken a punt on the three guys they've signed and it's important they hit the ground running."

Burke has racked up almost £30million in transfer fees but the 21-year-old has featured just five times for West Brom this season.

PSG teenager Weah – son of former World Player of the Year George – is largely untested too but Bayo did net 18 goals for Streda this term before sealing his Glasgow move.

But that pales against the achievements of Rangers' new additions.

Northern Ireland skipper Davis, 34, lifted eight trophies during his previous Ibrox stint while former England ace Defoe sits seventh on the Premier League's list of all-time goalscorers.

Sutton added: "One of the new Celtic lads may come in and explode – but we'll only know that in a couple of months.

"Brendan will be hoping one of these players work. I'm sure they have been watched over a long period of time but there is a reason why you're getting them for £2million or in on loan. They're in the development phase and with that comes a risk.

"It's about time Celtic started getting these deals right."

:: Premier Sports will screen the biggest games from the Scottish Cup for the next 6 years. Visit www.premiersports.com for details.