The 57-year-old, who took over from Alan Irvine at the Hawthorns earlier this season, admits the experienced duo help manage the West Brom squad when he isn't around.
Lescott was brought to the Midlands club over the summer, while Fletcher was a January signing from Manchester United, with both stars vastly experienced when it comes to top-flight football.
And the duo are a big help in the West Brom dressing room when Pulis isn't around, according to the Welshman.
Discussing Berahino, who Pulis believes has become a more mature player, the Baggies boss told reporters:
“Fletcher and Joleon Lescott and people like that will look after the dressing room when I am not around, which is lovely.
“It used to be like that when we were younger. If you have got a good group of senior players in the manager can sleep a bit better at night.”
West Brom host Southampton later today in what is sure to be one of Pulis's toughest tests at the Hawthorns so far.
The 57-year-old currently has the Baggies sitting in 14th place in the Premier League - five points above the relegation zone. The Saints, meanwhile, sit fifth but just a point behind fourth-placed Manchester United and two points behind third-placed Arsenal.