Doesn’t the finished bag look like a bunch of spring onions, or maybe a head of garlic? It’s just big enough to keep three tennis balls from rolling around your bag or car, and should be easy to resize for any sport.
Yarn: Your favorite dishcloth cotton. I used Lily Sugar ‘n Cream, and it looks like I have half a ball left, but I wouldn’t swear to it.
Needles: US4 dpns, US6 straights, and US7 dpns, circulars optional
Notions: charming decorative button, and needles for sewing in ends and button
Gauge: not critical; measure your knitting against the balls you intend your bag to hold
With the US6 needles, cast on 10 stitches for the bag collar. Leave a tail for sewing up the collar as you finish the bag. *Slip 1, knit 8, purl 1* every row until the band of knitting fits comfortably around the tennis ball.
For me this was 80 rows or 40 garter ridges. The collar should be snug enough to keep the balls from falling out of the bag, but stretchy enough that you can reach in easily and pull one out. Bind off the collar (knit the first stitch when casting off to keep the corner square), but leave the final loop as a live stitch and do not cut the yarn.
With US7 needles, pick up and knit a stitch from every garter ridge and join the knitting in a round, using the last loop from the bind off as either the first or last stitch. It will be easier to add more stitches on following rounds if you leave the collar unstitched at this point.
1. Knit one round plain.
2. Place a marker at the beginning of the round. *Yarn over, knit 1* for two rounds.
3. *Yarn over, Knit 2 together* for five rounds.
4. Knit one round plain.
5. *Knit 2 together* for one round.
6. *Yarn over, Knit 2 together* for three rounds.
7. Repeat rounds 4-6 twice more.
8. *Knit 2 together* for two rounds. Cut yarn, leaving a generous tail, and sew up the remaining stitches.
Sew up the collar and any loose stitches at the beginning of the bag.
With US4 needles, cast on 3 stitches. Knit I-cord for 5-6 inches. Fold the I-cord in half and stitch to the collar at the collar seam, leaving a loop.
Sew the charming decorative button over the ends of the I-cord.
Fill with tennis balls and admire your work!
A smart commenter on Ravelry suggested using this bag for dog toys (she actually said “dog balls” but o dear, insert your own spay-or neuter joke here)–please be encouraged to make these to give or sell for the benefit of an animal care organization. If you could let me know so I can brag on you, that’d be friendly! There is no charge for personal use of this pattern, but if you do use it, it would be nice to give an extra dollar to a deserving person or cause. Please contact me before making any other use of this pattern–I’m not inclined to drama or litigation. Thanks!
Peg of Tilling Does Some Knitting 
What a neat pattern! I don’t play tennis, but I can see this holding a ball of yarn. Thank you so much.
Thank you! I’m so pleased you like it!
can you make it to hold other stuff that’s not round like just a bag for knitting stuff?
You can certainly make it for other things! Knit the collar to the size you need, then pick up the stitches along one side to start the bag part. Try yarn over, knit one for increase rows, yo k2tog to lengthen the bag without making it wider, and k2tog for decrease rounds. Are you on Ravelry? Please post your bag when it’s done—I’d like to see how it turns out!
This is really cute. I’m not a tennis player so would you tell me: is loop meant to be functional or just decorative? Either way it’s a winner!
Thank you! I think the loop should be functional if you want to use it, especially if you add the carabiner clip, to hang the bag on a belt loop or gear bag strap, but nothing bad would happen if you leave it off.
oooh. My mother in law is a tennis player who is impossible to buy for because has everything she needs… Bet she doesn’t have one of these… Thanks!