Rizwan will join the club following Australia's tour of Pakistan, which ends in early April, and will be available for both first-class County Championship fixtures and Twenty20 cricket until the end of the T20 Blast in mid-July.

The 29-year-old averages over 43 with the bat in first-class cricket, including nearly 1,000 runs in 19 Test matches at an average of more than 42.

In 54 T20 internationals, Rizwan averages a stunning 50 with the bat at a strike-rate of 126.6. He has enjoyed a stellar 2021, becoming the first batsman to score over a thousand T20I runs in a calendar year

"In my heart, I know our young team has the potential to beat any team," he said in a club statement. "Our strength lies in our hard work, honesty, deep commitment, and self-belief. We can win, we will win, and we will play like champions, no matter what."

Ian Salisbury, Sussex's Championship and one-day head coach, said: "Mohammad's first-class and Test records speak for themselves and it's a huge coup to welcome him to Sussex for a big chunk of next season's Championship."

He added: "He and (Australia's) Travis (Head) are exactly the kind of experienced, international cricketers that our emerging lads can learn a huge amount from."