tennis would be a bit too far at the moment as i think your told to avoid twisting and shary turning whilst running for 9 to 12 montsh after acl repairs continue to straight line running, cycling, quads open chain light ex`s, range of movement should be near enough good leg and strength should be 4/5 compared to good leg in about 2 months (6 months post op) you start to run with gentle twisting, plyometrics, jumping on and off a step and controlled hopping. before you can begin this i would recommend gettin the strength and stability at the knee.#
Contact your PT or G.P nbefore doing any sports !!