London Irish boss Brian Smith has hailed Saracens' renaissance under his fellow Australian Alan Gaffney ahead of Sunday's Guinness Premiership clash at the Madejski Stadium.
Saracens arrive in Reading just one point adrift of the title play-off zone, having won four from their last six league matches, while they are also firmly on course for a European Challenge Cup quarter-final place.
Saracens also boast the Premiership top points-scorer this term in fly-half Glen Jackson, with centre Andy Farrell and flanker Richard Hill also beginning to make their presence felt following prolonged injury battles.
Smith said: "We will be facing an in-form Saracens. Alan Gaffney has worked his magic on a talented squad of players.
"Wherever you look, there is real class from full-back through the backs to the tight five and back-row.
"We are expecting as tough a game as any we have played all season, and know we will have to be at our best to secure any points."
Smith will make a late decision on 20-year-old Shane Geraghty, who was named in England's Six Nations squad earlier this week.