The Polish international impressed on his Ewood debut, pulling off a string of saves to ensure Rovers kept a clean sheet in their 2-0.
The Rovers boss was delighted with the display of the 23-year-old and hopes for a similar outing against Huddersfield Town this evening.
"I thought he was magnificent on Saturday, he made some vital stops for us," said Bowyer.
"We know he can produce that and we'll be looking for the same again.
"It was his job, if they break the back line then he has to save the day and I thought he did that well and he can only grow in confidence from that."
See Sandomierski and the rest of the Rovers squad in action this evening at Ewood Park against Huddersfield Town.
Tickets will be on open sale up unti the 7.45pm kick-off, priced from £19 for Adults, £12 Seniors and £7 for Juniors Under 16.