Neil Back fancies a career in coaching when he finally gives best to the ageing process and retires this summer, which is probably as well, given that he will spend the first three matches of the British and Irish Lions' tour of New Zealand on a watching brief.

The Leicester flanker is currently in the early stages of a four-week ban, and while he received plenty of support from the Lions head coach, Sir Clive Woodward, yesterday - some of it ill-advised, it has to be said - his chances of making the Test side for the first meeting with the All Blacks on 25 June are less than great.

The suspension was imposed by the Rugby Football Union on Thursday night after a disciplinary tribunal considered the circumstances surrounding Back's nasty punch on the Wasps forward Joe Worsley during the Premiership Grand Final at Twickenham last weekend.

"There were significant aggravating features," said the panel in its judgement. "The punch was intentional and delivered from a position out of Worsley's sight, Worsley being taken unawares. It caused significant injury. Importantly, Back is a role model and his conduct should be commensurate with that position.

"This offence was very public and brought significant discredit to the game. Any sanction for an offence committed in such a public manner must contain a significant element of deterrence to give a message that no matter who the player, this sort of conduct is unacceptable."

This judgement contrasted sharply with Woodward's impression of the incident. "I think four weeks was harsh and I am disappointed, as is Neil," pronounced the knight of the realm. "I can't really understand how they reached the decision. I believe Neil has grounds to appeal, but at this stage of our planning, it seems advisable that we move on and focus on the challenge ahead. Everyone involved in the tour recognises the special qualities Neil brings to the game, and he will have a crucial role."

For his part, Back said he was "surprised" at the severity of his punishment, but agreed with his coach that his energies should be devoted to the tour rather than to any appeal. It was a wise approach.

Despite Woodward's astonishing assertion earlier in the week that "Neil thinks he is innocent", Back has admitted to "genuine remorse" at throwing the punch.

Back had already been omitted from the Lions side to play Argentina in a full international match at the Millennium Stadium on Monday night, and will now miss the tour games with Bay of Plenty, Taranaki and, perhaps crucially from the player's point of view, the New Zealand Maori in Hamilton on 11 June. In effect, he has one Saturday match - against Otago at Carisbrook on 18 June - in which to see off the intense competition certain to be mounted by the likes of Martyn Williams and Lewis Moody for the Test open-side position.

Argentina, badly affected by club demands on their players, have awarded the captaincy to Felipe Contepomi, the gifted midfielder who played Premiership rugby with Bristol before joining Leinster, a move that allowed him to complete his medical studies at Trinity College in Dublin.

Mauricio Reggiardo has emerged from international retirement to play at prop, and he will be joined in the front row by Federico Mendez, who will almost certainly call time on his long career at the final whistle.

Argentina (v Lions, Millennium Stadium in Cardiff, Monday): F Serra; J Nunez Piossek, F Contepomi (capt), L Arbizu, F Leonelli; F Todeschini, N Fernandez Miranda; J M Leguizamon, M Schusterman, F Genoud, M Sambucetti, P Bouza, F Mendez, M Ledesma, M Reggiardo. Replacements: E Guinazu, L de Chazal, M Carizza, S Sanz, L Lopez Fleming, F Bosch, B Stortoni.