Ospreys have claimed 14 victories in 24 matches this season, winning more games than the other three regions Cardiff, Scarlets and Dragons put together.
While locks Adam Beard and Rhys Davies are injured, in-form Ospreys such like Morgan Morris, Nicky Smith, James Ratti, Reuben Morgan-Williams and Keiran Williams have again been overlooked by Gatland.
The Wales coach acknowledges the Ospreys’ success, but has also marked recent 60-point losses against the Bulls and Leinster.
“When we look at performances, we look at players and what we can do in terms of developing them,” said Gatland.
“We don’t always look at club performances… and sometimes we look at club performances against big teams when they’re fully loaded.
“You talk about the Ospreys and it was a good win for them on the weekend (against Cardiff).
“But you look at games when they played against the Bulls and Leinster when they were fully loaded and we make those sort of comparisons.”
Prop Smith, who was named player-of-the-match against Cardiff with a two-try display, leaves Ospreys for Leicester in the summer.
The 30-year-old has won 46 Wales caps, but Gatland has decided to stick with his three Six Nations loose-head props, Gareth Thomas, Corey Domachowski and Kemsley Mathias.
“Nicky has done all right,” said Gatland.
“It’s about continuity in selection in a number of positions.
“We know what Nicky can do, and with some of those players we want to keep them in the squad and develop them.”
Uncapped number eight Morris is one of the most consistent performers in the regional game, but has not been selected with Aaron Wainwright and Mackenzie Martin the specialist number eights included.
Gatland says Morris’ defensive work must improve.
“It’s not just the attack stuff, it’s both sides of the ball we look at,” said Gatland.
“When we go through the videos with players, it’s not just the stuff we look at around the ball, we look at things off the ball.
“He’s had some really good games for the Ospreys, we’ve got a lot of players in those positions as well.
“For him, it is about working and making sure he does do things on both sides of the ball, not just from an attacking perspective.”
