While eighth-placed West Brom have stumbled slightly in recent weeks, winning just one of their last six games, Southampton have moved ever closer to Premier League survival by going unbeaten over the same period.
The appointment of Pochettino following the dismissal of Nigel Adkins, who had led the south-coast club to consecutive promotions, was not universally popular with Saints' fans.
But he has delivered during his three months at the helm, notably with wins over Manchester City, Liverpool and Chelsea.
Southampton are eight points above the drop zone after their goalless draw at Swansea, compared to the three they were clear when Adkins was relieved of his duties.
And Clarke believes Pochettino has given the Saints a hard edge.
He said: "He (Pochettino) has done well. It is difficult to come in and pick things up halfway through the league season.
"He has got a good group of players and earlier in the season when Nigel was there they played good football.
"I think at that stage the players were searching to find their feet in the Premier League.
"The change of manager has coincided with them finding their feet in the league. They play good football, they are attractive - certainly at home they are dangerous. It is a difficult game for us.
"His team has been a bit more aggressive - something we have spoken about this week and something we have to deal with. You will see the results on Saturday."
Many had tipped Saints for relegation but Clarke has not been surprised to see them prove their critics wrong.
"When I look at the talent on the squad it does not surprise they have got where they are," he said. "You might feel they need a win to be safe but they are pretty much safe and I am sure they will be in the division next year and stronger for it."
West Brom appear to have little left to play for after an excellent first campaign with Clarke at the helm, and are currently on course for a top-half finish.
Their cause this weekend will also not be helped by the absence of captain Chris Brunt and midfielder Youssouf Mulumbu through injury and suspension respectively.
But Clarke wants to avoid the season petering out.
"We would like to finish well," he said. "There are five games to go - so let's pick up a few more points and make it a season we can look back on with satisfaction."