The Canadian international goalkeeper accepted the opportunity to head to Kenilworth Road for some first team football but, after featuring in three games for the Division Two side, was laid low by a bad dose of flu that forced him to miss the victory over Mansfield.
Then, just a game and 20 minutes into his return, he picked up a nasty hamstring that could well end his season.
Nevertheless, Lars has at least sampled the culture of league football and he certainly enjoyed the competitive nature and the chance of first team outings.
"It was good, I hadn't played for a while, since Sully came back, so it was great to play some first team football again," said Lars, who added that the more robust style should help him along in his development.
"There is more route-one football, a bit more direct with the ball being pumped into the box and it gets a little more physical at times.
"It keeps you aware of different things and that helps your game. Training here at Spurs you notice that the guys are a bit more polished in the things that they do. It's more physical in the league so it does help.
"I then came down with the flu for about a week and unfortunately I had to miss a game."
He returned to action in the 1-1 draw with high-flying Wigan before, in the process of making a save against Oldham in the following game, sustained a hamstring injury that required a scan and could end his season.
"Playing against Oldham with about 20 minutes gone I went to save a shot and pulled off quite a funky move. Basically I did the splits and heard a pop in the back of my leg - it was over then and I knew something was wrong."
It is fair to say that Lars Hirschfeld has experienced mixed fortunes during his loan spell at Luton Town.