England limped to a 1-1 draw with Denmark on Thursday to remain top of Group C and keep themselves on course for a spot in the knockout stages.
Victory would guarantee England finish top of the group and avoid a potential nightmare round-of-16 tie against Germany.
But they will also be keen to show tangible signs of improvement after their drab draw with Denmark and Sutton believes Southgate must be bold to get his side firing ahead of the knockouts.
‘He’s got to be ruthless now, hasn’t he because things haven’t been working,’ the former England striker told Metro.co.uk.
‘I think I was very excited before the tournament by the attacking players England had at their disposal, but they haven’t clicked as they should have done.
‘A lot of people are talking about off the ball but on the ball in the final third it hasn’t been as productive as slick and the combinations haven’t been there like I expected.
‘When you strip it back, England have four points and are in control of the group, but I suppose they are all looking at Spain and Germany and their performances and I think we’ve got a long way to go to get to that level.’
After two unconvincing displayers alongside Declan Rice, the experiment with Trent Alexander-Arnold in central midfield appears likely to be called off for England’s final group game.
Against both Serbia and Denmark, Conor Callagher came on to replace the Liverpool star, but Sutton would rather see a more attacking switch to crowbar Cole Palmer into the side after his superb maiden season at Stamford Bridge.
How England could line-up against Slovenia
‘It looks like Conor Gallagher will come into that position, but I’ve got to say one thing which I have found quite baffling is the omission of Cole Palmer,’ he added.
‘I think given the season he had at Chelsea, it’s quite baffling for him not to have been given any game time in the opening two games.
‘I would play Rice alongside Jude Bellingham because he can be a six or an eight or a 10 and I would find a way to get Cole Palmer into the team. If we’re searching for that bit more creativity then he’s the perfect player to provide it.’
Chris Sutton has teamed up with Greggs and Just Eat to launch xGreggs (eXpected Greggs) as research reveals the UK hates complicated football statistics. The more goals from England and Scotland this tournament, the more free Sausage Rolls for everyone. See just-eat.co.uk for more details.
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