With three points in the bag against Albion, Glenn watched on as Everton lost their second-successive game and Blackburn were held by Bolton.
The results left us six points behind Everton in the UEFA Cup chase - the boss knows it would have been just three if we had performed and produced the goods against Manchester City on Friday.
Glenn said: "What is so frustrating is we're watching the results coming in and the Manchester City result is the thorn in our side.
"We would have been three points off now if we'd have won that game.
"The results have gone well for us and we would have been three points behind Everton and well in the hunt.
"We've a tough one against United at home next of course but the crowd and the team can really get up for that one and we can win that game.
"Europe is still a possibility but if - that's a small word but it means a lot in football - we'd done better on Friday it would have been three points and that is so frustrating for us."
Glenn Hoddle admitted his frustration as he watched the Premiership results roll in at West Brom on Monday.