The defending Premier League champions were emphatic 5-1 winners against Manchester City’s second string in the FA Cup fifth round at Stamford Bridge last weekend.
Hiddink has only lost once since taking over the Chelsea reins for a second time from axed manager Jose Mourinho in December.
Paris Saint-Germain inflicted the first defeat of Hiddink’s second spell after goals from Zlatan Ibrahimovic and Edinson Cavani in the first leg of their Champions League last-16 tie earlier this month.
Former Aston Villa and Everton forward Gray believes Southampton have enough quality to keep the defending champions at bay.
“Chelsea need to go and play this game. Take their focus off of the FA Cup, off of the Champions League and work their way up the table,” Gray wrote on Paddy Power’s blog.
“They’re 12th now, they’ll want to get into the top 10. I think they’ll play their best side available.
“They go to Norwich on Tuesday but won’t be worried.”
Gray added: “Southampton are decent and are in that cluster of teams that are fighting to get into (or stay away from) the Europa League.
“I’d be hedging my bets.”
The Saints are in sixth place in the Premier League table and seven points clear of 12th-placed Chelsea ahead of Saturday’s clash.
Southampton were 3-1 winners against the defending champions at Stamford Bridge earlier this season.
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