Vennegoor has been out of action since October after tearing his abductor muscle in a game against Hamilton at New Douglas Park.
He admitted: "Normally, if you have a few small injuries it is not bad. But now it is one big one which kept me out for almost two and a half months. It's a shame you can't play, especially in the busy time from October to December when you have vital games in the Champions League and the SPL.
"You want to be involved in these. If you can't, then you are a little bit frustrated because you are looking at it from the side. But these are the things you have to deal with and now I'm fresh again and almost want to eat the grass and play football again."
Big Jan then revealed the problems that caused such a lengthy lay-off for an injury that is normally quite routine.
"It was a quite interesting injury because it doesn't happen often," he said. "A piece of adductor muscle was torn off the bone. It needs time to settle down and heal because it is not a normal muscle tear. It is in a sensitive area, but it feels good again."
Jan has struggled throughout his Celtic career with injury and the team does miss him when he doesn't play. Whilst not gifted enough to make the same kind of impact in a match as previous incumbents of the central target man role Jan's presence has been missed. "Last year, I had a good year, and this year I was doing okay," he added. "Then I got a kick playing against Falkirk and needed stitches."
Jan realises that he will have to win back his place in a quietly efficient Celtic forward line that, although it is far from being prolific, has performed better than previous recent seasons.
"Competition is something you have to cope with as a footballer. It makes you stronger and keeps you on your toes."
Let's hope that you manage to keep yourself on your toes a bit longer than usual Jan!
Yours in Celtic